Tabasco Cat badly injured Jeff Lukas, he didn’t kill him. Also, TC was quite hot but he didn’t attack Jeff. He got loose and was clearly badly spooked and ran over poor Jeff.
Remember, when discussing any sire line that (especially once you are talking about a grandsire) you are discussing ONE individual horse within a pedigree. Because stallions have so many offspring, t’s easier to discuss their propensities but it’s often the case that since the foal is at the mare’s side for months that SHE is the influence for whether the foal is a dominant or submissive type.
Just like with show horses, there can be huge differences between how young race horses are trained and raised. That plays into their demeanor as does when (if) they were gelded.
Remember too that when a track person says a horse is tough, they might mean the type of mental toughness that makes a good competitive horse. (That kind of “tough” might translate into a very nice competitive jumper or eventer or even hunter. They are the ones that want to work and do well.) They might also mean a stubborn moron that simply has his notions about everything. The latter type can be a pain no matter what you want to do with them.