Welcome, Teecah.
I agree that the alerts seem somewhat bizarre. The tiny blue pair of shorts (the first thing he throws up in the air and barks at) isn't on the list. He didn't throw up a woman's blouse, but that is on the list. If the nuzzling is the cue, then the grey/green man's T-shirt isn't on it, either.
Grime didn't have the notes on what he was supposed to have reacted to, the PJ did. How they came to their conclusion remains a mystery.
I tend to agree with you.
It would have been better to place each item in an individual bag before placing in box.
And to have the handler state exactly yes this item was alerted to, no this item was not alerted to.
However it may turn out not too important exactly which clothing items were alerted to.
IMO all the clothing items alerted to (whether one chooses items listed, or items thrown in the air, or items nuzzled) are simply items which were in a pile in a cupboard, and were not being worn at the time when some of the items in the pile came into varying degrees of contact.