without even clicking on the video, first thing I noticed was the lateral head of the tricep that pops out. on the hulk dude.
if he's training for strength, and his videos are 'exhibitions' of strength, I really can't see him doing site injections in his triceps, as to me, logically, that'd decrease his pressing ability.. his 'calling card'.
I've known big dudes (meaning guys who train for size/strength and are 15-20%+ bf and dont' give a shit) with some 'freaky' bodyparts like triceps or delts or traps... I dont' see this dude doing site injects in the tris.... plus, at his bodyfat, it'd be difficult to place the needle correctly and getting each site uniform.
if he's a strong presser, and pressing is LARGELY triceps, and he's a big dude, I can very well see him having some large triceps.