Originally Posted by ATW525
...I'm only familiar with the IDPA definition of the term which amounts to "Everybody gets firsts before anybody gets seconds" which doesn't appear to be what occurs in the scene.
And isn't always the best idea.
In the situation shown in the film, Threat 1 was close and with his gun deployed. Threat 2 was more distant and hadn't yet presented his gun; in fact he was struggling to get it out of "deep concealment." Threat 1, therefore, was considerably more serious and needed to be thoroughly neutralized immediately. Threat 2 was less exigent.
Of course it was all staged to work out that way. But it does illustrate an appropriate tactical sequence under those particular circumstances.