Football can be emotional. (That is, in fact, the very nature of sports in general; just ask Hal McRae.) Those that play at a professional level are passionate to the nth degree—they'd have to be to be anywhere near good enough to be respected.
And, that is not specific to players. Coaches can be caught up in the heat of the drive, the competition, the deficits just like anybody else.
Here are some entertaining examples of "caught up" coaches in the NFL.
Warning: Some of the videos contain NSFW language.