When Dekker is yelling at Slater to stop during his first appearance, it normally sounds like the typical thing he does whenever he is on screen (unintelligible angrish). However, the look on his face and the stuff he's saying sounds more out of concern for Jack. Turns out this was because he knew Jack's son was one of the hostages and he was merely trying to keep Jack from being too emotionally involved in the situation.
The off-screen moment that Danny describes, where Jack saved Dekker, who generally does nothing but yell at him, from public humiliation.
Jack worrying about his Action Girl daughter, and that she should be looking forward to prom, not field-stripping an AK-47 ...
Danny's mom bringing out Jack's more sensitive side.
Jack's Aside Glance at the end. Normally, it would be Leaning on the Fourth Wall, but in this case, Jack knows there's a fourth wall and his glance is directed to a specific audience member, Danny.