I guess it must be part of making a topre cap, all of my topre brobots have been super easy to come off. That is definitely a shame though.
It isn't a part.  I've been trying my hand at Topre caps.  Some do come out loose, but I mark those as seconds.  Most come out with a tight stem though.
look at dat mummy fly!
I was wondering what cap that was.  I know some of my early caps have that proclivity.
Dat 120g blue switch tho XD
Holy crap. That thing must sound like a machine gun.  I could see why that could launch some caps.
Demand a refund.  Everywhere you can.
It was a trade, so can't.  Like I said though, I don't think they have any Topre boards and it was pure ignorance on their part.  I'd rather see if I could get CC to repair the stem.