To ME, blatant sandbagging is when you see kids who without a doubt could and should be competing at least one, if not two, levels above where they are competing. If you know someone HAS all L7 skills and they are competing L4/5 with the intentions to make their gym win, that's "wrong", IMHO.
If a gym routinely repeats most levels with the sole intention of winning, that's "wrong".
However, there could be plenty of other factors and we don't always know. Sure, we had a few L4 and 5 repeaters last year BUT they repeated for good reason. Two of our girls who competed L5(one repeating, one new) had ALMOST all their L7 skills really well but each had some hang up on one skill. So yes, they scored really well and probably looked TO OTHERS as if they were sandbagging when in reality, they couldn't have competed L7 last year. A few of our repeaters didn't get their L7 skills in time so had to repeat 5, for good reason. Some of those girls may end up repeating L5 again... They didn't sweep the podium or anything though, they were very appropriately placed even though they repeated.