A Sword Dancer said:
Seems most likely that rather than Goku having some time hax resistance or grace period from time attacks, that Hits time stop ability is powered by Ki and you need to use some amount of Ki relative to the Ki or physical power of the target in order to stop them. Goku pushed through it the first time because he powered up and the amount of Ki Hit was using wasn't enough anymore.. and then he increased the amount of Ki and bam suddenly it works.
So it's not a hax resistance feat rather than just another 'power level' feat.
I mean sure it is powered by Ki, but it's still actual time-stop hax, dude. The definition of time-stop hax is that the guy can stop time for his opponent while still moving himself. Against any opponent up to a certain level of power, he can stop time.
What this also shows is something about the mechanics of powers in DBZ: That high-level (Godly) Ki can allow for time-stop hax and/or resistance to such hax!
Just because the hax is powered by a non-typical mechanismm for such hax, does not mean it isn't still hax. Nobody really even questions the fact that Hit has time-stop hax, dude.