superboy...something you have to understand is that just because ZBT didn't use L/R hand technique doesn't mean that he's better WITH it in that situation.
every time you mentioned ZBT not using L/R hand technique, ZBT is using vacant fist against a strong opponent: GWM, YG. why do you think this is? it's simply because he needs both hands using the 72 kong ming fists to overcome the ferocity and speed of GWM and YG's attacks. if ZBT were to use L/R hand technique here, he would simply lose because he could not defend against GWM's quick and powerful strikes with only one hand.
as to why ZBT can use L/R hand technique against YG:
1. for goodness sake, YG only has one hand to use. true, he has overcome his handicap, but i'd think that he would have a hard time striking as many times as a 2-palmed fighter (aka GWM) can in the same given amount of time. it's easier to intercept YG if he's just using straight up palms. that's why elusiveness is such a big factor of sadpalms --- if the opponent doesn't know where YG is striking from, then it doesn't matter if he hits less times because each hit will be effective.
2. ZBT was on the offensive when he used L/R hand technique against. never do we see ZBT use L/R hand technique to stop an all-out assault from YG. in fact, my theory is that when ZBT needs two hands to defend, he simply cannot do L/R hand technique because his full defense can only be effective when using 2 hands to block.