In the gymnastics, I thought some of the early scores were questionable, but I think some of that was missed because live swimming was being shown, so it was tough to get a feel for the scoring in an entire rotation. The scoring in the last two rotations seemed fine to me, and not just because the US finished 1-2 and the announcers stopped bitching (I'm no expert, but I come up with a score in my head before seeing what the judges do, and in the last two rounds most scores were close to what I thought they should get).
Overall, I think the judges are still getting used to the separate difficulty and execution scores. If a routine's execution is a 9.0, the person doing the tougher routine might have a 7.0 instead of a 6.0 on the difficulty. So that score is whole point higher, which is a helluva lot. But it seems to me that the judges give less deductions in the execution score for the tougher routines, giving the harder routines a double bump.
I think that's generally been true for both the men and the women, regardless of country.
In the tennis, I'm assuming Blake wasn;t allowed to ask for a review? I didn't see the match, just a replay of the highlights. Things like double bounces and deflections off the racket/player should simply be added to the replay challenge system. It could have been corrected on the spot if Blake saw/heard it live and asked for a review (I thought the deflection was clearly visible on the replay).