3/4 bf rated at 30gpm 1" rated at 50gpm they got what they paid for. don't know if where your at if they needed a permit and where's the tag.
Permits have not been pulled here for the vast majority of anything other than new construction since code enforcement started here in 1998, but that is changing. This is one example of why.
Last week, I found out that the company that installed this one didn't have anyone trained in backflow testing.
They called me out to test an RP Friday. It failed almost immediately due to a leaking #1 check valve. If they had a tester they could have fixed in just a few minutes before leaving the job.