All spotters are Volunteers?
Depends. Usually spotters are come by in one of three ways for meets - 1) Sometimes they're paid, usually $75 - 150 a day are the rates for bigger meets I've seen. 2) Volunteers from powerlifting teams or friends of the other lifters / sport that want to give back. These guys are usually comped in certain ways - meals, shirts/souvenirs, reduced rates for other meets, etc..... 3) Whatever cheap labor the meet director can find.
What I've heard is that originally is they were going to use a few powerlifting teams from the local military base, but those volunteers couldn't make the meet, so they got those local kids to spot. They also wouldn't let any established female lifters act as spotters or loaders in the smaller weight classes. There were tales of those kids not being able to handle the plates and dropping them on their feet, etc.....
Also there was unhappiness over how a medical / first aid situation would be handled, and how general things like hotel bookings were handled.
All in all, no one had much positive to say about how that meet was handled.