Tech A taking sample is not Tech B counting sample. Tech taking sample has considerably less experience than Tech counting sample. Cross contamination is a possibility (and leading theory amongst people of a higher pay grade than I), but I believe the sampling tech to be competent to prevent CC, just as I have faith in the counting tech and their experience with these issues. (I should say now, I am not Tech A or B... I am Tech Z, just trying to assemble the puzzle as well.)
it does look like tech A is the "source",....
problem is how?
where did Tech A acquire the envelope?
why would a ready for issue envelope have contamination inside it?
it's not that easy to dam near impossible to inadvertantly cross contaminate the interior of an envelope through standard handling methods,...
you have to intentionally load something into the envelope,...
so, my 10,000 foot view is:
Tech A grabbed an envelope from somewhere other than normal protocol for reasons known only to Tech A,...
turns out that was a FUBAR move,...
and now Tech A refuses to budge on the envelope origin backstory for reasons known only to Tech A,...
everybody has done something that seemed easy enough but, because of the implaccable, unforgiving nature of radionuclides, it turns out that the most inane of reasons for doing things "just so" is buried in thousands of man-years of operating experience and was learned the hard way long ago,...
it is also why we throw away so much stuff that looks clean and pristine but is not proven clean and pristine; the man hours to prove it are far more expensive than trashing the suspect product and buying new product, even with a SAM only two buildings away,...
it would be so much easier for everybody to document this as a HU area for improvement and move on,...
without that, this becomes a monotonous "chase down all the possibilities and rule them out" paper chase,...
and it's holiday season,...
then again,...the world is rife with cross contamination in new product issues nowadays,...