My impression is that John Mack worked with Cynthia Hind in investigating this case [there even seems to be a picture of the two of them together in a classroom at the site I linked] and that one or both of them wrote about their investigations at the school. We'd need to read those texts, I think, and as much as we can of what the children, teachers, and parents said after the event, to understand whether the children were "led" by Hind. I for one consider it a hopeless task to attempt to find out the backgrounds, psychologies, and reliability quotients of all the witnesses to CEIII events reported and investigated over the last 50+ (and probably more) years. I also think that no amount of such investigation could overcome the weight of the descriptions of the 'lived realities' of these experiences and their persistence in memory.
What's fascinating are some of the follow up memories that the original interviewees have when they are older. For them the event is still visceral and uncanny. But we also know that memories, unfortunately, are only as accurate as the last time they are recalled. This allows for perpetual erosion and corruption of the memory. It is their original interviews that has the most value. On a side note I find it fascinating that when we forget an intense memory, and thn suddenly recall it, the memory floods back like a hammer to the head and all the memory of the original event comes back with great force and accuracy.
However, interviews with the whole collection of kids and aduts in Zimbabwe would yield the best results. There is an issue of contamination though in that whatever initial conversations that were had in groups create opportunities for a lot of consolidation of ideas, events and imagery. While there is some variation in imagery, which is perfectly natural, though the range of descriptions of the humanoids is quite curious.
In the work by those interested in identifying mass hallucinations as the reason for why people saw Jesus rise from the dead or why those at Fatima saw the Virgin Mary (though I prefer Vallée's and other Ufologists' interpretation of that spinning disc as a UFO) they identify some interesting features that could explain a bit of the mechanism that could be at work in Ariel. If he right emotion and expectation is created then imagery can be pre-created, and a collective hallucination could unfold given the right conditions or even possible mundane stimulus. I know that fear can make people highly suggestive and a lot of weirdness can unfold without too much extra assistance.
I think you have to go back to the Cathars to find the kind of 'mass hallucination' you're looking for, and even then we can't be sure of what was experienced by those involved. I think most sane people, including children, have a grounded sense of what they experience, even in abnormal situations.
Examples of conversion disorders affecting large groups of people having physical and mental symptoms are as recent as the late 90's and beyond with a number of odd cases: fear of genitals being stolen, sudden rashes breathing ailments and anxieties, spontaneous contagious episodes of laughter, fainting and breathing issues and other odd weird events that have no organic cause, but in the Kosovo school children case that affected only ethnic Albanians it demonstrates how stress and anxiety in the populace can lead to such events of strange group delusions and physical manifestations of collective illness. an nteretnt feature of conversion disorder is that groups of women appear to be a central feature of conversion disorder i.e. factories and all girls schools are a repeated theme.
I agree though, collectively seeing aliens and a craft out in the back of the schoolyard is a different matter altogether. However, if the germ of such an idea is what is convincingly spread at the outset then I can see the possibility of a mass hallucination occurring, especially if here is enough fear traveling through the group. Groups of people in fear are highly unpredictable and unstable bodies. In researching mass hallucinations there really isn't a lot of strong consistent work or cases around this historically. But then think about the bloodlust found in crowds around the world that drag criminals out of prison to meet mob justice because of how they broke everyone's reality. It corresponds to a shared shift in values and perceptions in a crowd of people that will beat out its will in the bloody streets. When reality breaks all bets are off as to how a group might respond. Perhaps I've watched
The Night that Panicked America too many times?
But the part where Ariel gets really strange is the sense of telepathic communication unfolding, and as you have pointed out this is a repeated occurrence in some cases with crafts on he ground. This does help to elevate this case and suggests that the nature of the external stimulus is physical, unique and interactive. I find it very curious that when we look at groups of cases that are most convincing it is the two well known school children cases that people focus on. The only person I personally know that has had a significant UFO sighting happened during her Grade 8 graduation ceremony outside on a field in Trinidad, where the whole school and parents all watched a glowing metallic cube tumble across the sky, stopping the ceremony until it suddenly took off, as UFO's will do sometimes.
Eyes, I still feel are easy and natural portals for all creatures. Staring at some dogs makes them go crazy and violent. It I don't stare into the half Husky eyes of my dog he feels uncertain of his place in the pack. Like with my cat before him, I routinely engage in telepathic communication with my dog and we appear to have excellent understanding of each other. My cat was an exceptional therapist for me and brought me through some very difficult times. Unfortunately, none of this has improved my telepathy with my partner in any meaningful way. So, if in fact these kids stared into the eyes of an alien creature then I would be surprised if there was not some reporting of some kind of a dialogue. There's an inevitability there along with the fact that the messages are often the same environmental pleas. The one where the witness reports the alien telepathically communicating to her to not to bother him because he could crush her like a bug is the one I find to be hilarious and disturbing at the same time.