Overall opinion: meh
However - it does make me question the choice. Walking in and amongst a bunch of fired casings with essentially covering your feet is a pretty easy way to step on an upturned case just right (wrong?) and get a really really nice puncture wound.
Wearing flip flops when you're out and about and the ish hits the fan is one thing... But to automatically put yourself at adverse risk for puncture wounds of stuff that's been sitting in and on the ground for who knows how long? THAT makes me question the decision-making skills of the individual.
To further muddy the water: If this was strictly a marksmanship / accuracy class - then double-meh. But if it was any kind of SD class involving movement in and amongst a ton of range brass on the ground - then things get hinky.
Exactly. Almost all classes have rules on what you wear to a class (like hearing protection and eye pro) and many have recommendations on clothing to avoid injury. Flip flops in a shooting class is stupid.