Yelling isn't great, but in high-stress situations, it can happen. What I take away from the "4 or 5 times in 13 years" is that it shows that the yelling was probably meaningful. I suspect Steve was reacting authentically rather than being a constant yeller. Ironically, I suspect he yelled because he cared. I'd rather work for someone like that than places where people don't yell because either they don't care, or they're passive aggressive.