Wheelbuilding / Wheel Building / Wheel build help

Thanks for the replies.
Got it but slightly bummed that his statement didn't stand true.
Possibly the differences he encountered in wheel strength, between wheel-sets were attributed solely to the quality of the build itself, e.g., one properly laced wheel set not tensioned correctly vs the subsequent ones laced like this but with more attention/experience...
He was quite confident with his workmanship and claimed to have experience in mtbing, offering a full refund if anything went wrong too.
Would you consider it inappropriate to ask for a small refund to get the wheels rebuild?
I don't know how to play this one out.