Here's what they actually said about it - remember the Canadian government is actually remarkably open about this stuff:
Emphasis is mine, but it should be clear: the dude was lying about drinking, and couldn't find the spot weeks after it occurred.
So the dude went back on his own, found the site, and found the evidence for the encounter.
On his own.
When he couldn't find it a month earlier.
Only after the RCMP wanted to close the case because they didn't quite believe him.
This is the bit that gets everyone excited, right?
Except there were follow up activities:
In other words: it was stuff widely available, wasn't a lot of it, and wasn't actually a problem at all.
Remember, this is close to where they actually mine the stuff.
So which is it? He wrote a book and sold it, or he didn't financially benefit from it?
https://www.collectionscanada.gc.ca/ufo/002029-1300.01-e.html (Library and Archives Canada)
There was no evidence of Michalak being exposed to radioactivity at all if you read the reports. He was tested, and found clean from all radioactive sources.
And this piece of metal:
I don't know where he got it. But why assume it's related to the incident at all?