The question is, what kind of radiation was detected, alpha,beta or gamma and in what ratio?
factoid: A granite countertop is detectabe with a Geiger counter.
"The objects, one appearing to be a pipe bomb and another that appeared to be a paint can". Factoid- most paint cans do not show much more than background. I have never personally checked a pipe bomb with a Geiger counter.
So... we can pretty much take certain levels of radiation for granite?
My theory is that it's those dadgum tamales they serve there; that'll light ya up!
I don't claim to know what happened, but one of the carnies had an old Buster Brown Foot X-Ray machine.