Did you measure to make sure it is long, wide, deep, etc enough? Add about 6" for the shell and plaster. It is a good idea to be there just in case they have any questions or ideas while doing the work. There have been times where they come up with some good ideas from doing so many.
Agree with all of the above...although the time to measure was probably before the steel went in. But, redoing steel is certainly better than after its shot so can't hurt if you thin it's off (and would be willing to fight about it). Also, the shell/walls in our neck of the woods is typically 1'. I'm sure crews sometimes offer good suggestions. Others may take shortcuts. Sounds like you are working with a builder so really, it's his job -- you can complain to him but he's paying those guys not you so there isn't much you can do really.
I was not happy with my shotcrete team. I read extensively about how shotcrete is supposed to be applied and what to look for re: shortcuts. When I voiced complaints to the PB, he basically told me I'm worrying about nothing... They literally took every shortcut the articles I read said they would take that end up compromising the integrity of the shell:
- they used backerboard to form the walls of my 18" bond beam and the weir wall between the pool/spa...I could see it moving while they were shooting...looks like they did a better job for you on that
- they shot the walls first which means excess material just dropped to the floor; material that doesn't stay where it is shot is supposed to be removed (rebound); the proper technique is to shoot the floor first so that rebound can be removed as it falls...
- they didn't appear to rewet areas that they had to come back to after a while (it's fine/unavoidable to move from an area and then need to come back to it...after a certain period of time they are supposed to rewet the surface before returning)
- the aggregate also seemed a poor mix to my (completely uneducated) eyes -- I have crevasses that I can stick a long nail completely into; my suspicion was reinforced when they had to come back to fix an area they missed (a bench) and that section is much, much different without any of those types of gaps present... I'm not saying it is supposed to be smooth -- but deep pockets of air aren't supposed to be present either
- there were some areas that were not shot as thick as they were supposed to be; a few even with exposed rebar...meaning, it was literally 3" too shallow in areas
...and mind you, there was an inspector there the whole time as well. The inspector never returned my calls to discuss the job, instead I was mailed a report from showing the sample taken came back with sufficient strength.
A builder I hold in high regard said the only way to get a crew to shoot it properly is to set their expectations they will do so and hold them to it. That will be on your builder since they are doing it for him. You're only real option would be to stop the job if you don't think it's being done properly which obviously jeopardizes your relationship with the builder.
...and now for some balance to all of this concern...based on what I've heard from everyone in this industry, most pools are shot with the same practices used to shoot my pool and most pools don't seem to be failing quickly. So, maybe the over-engineering required here in CA offsets the poor practices used to shoot our pools. I dunno.
Good luck!!!