Weird Wolverine PBS1 broken collar

Was shooting my East German AKMS-K 12.5” sbr in 7.62x39 today with Wolverine pbs-1. After about 75-100 rounds I noticed the can was coming loose. Stopped shooting and upon inspection noticed the 14mm locking collar has identical breaks in the metal on both sides. WEIRD! Called dead air today and they told me they would ship a new locking collar to me by emailing [email protected]

Anybody have any idea how this is possible?