I think all Huma regs work that way with the little plastic disk.
Have 2, for FX and for Leshy / epic 2 and its the same basic principle / design
Ill be damned if i have a good idea as to why that piston can get to look like that, my understanding is it is the plastic disk that is supposed to break if you misuse the REG.
So i would be inclined to think it is a production issue, though also hard to see this little part get dinged up like that during that.
I would contact Huma, they are nice peeps