I just watched it.
As a former Marine, that surprised me too.
I can't imagine ANY US Marine Squad Leader or Fireteam Leader undergoing a combat mission allowing a Navy Seal to commandeer his squad in order to "teach" them how to clear houses.
If this is, in fact, in the book, I'll have to chalk it up to literary license as he used in punching out Jesse Ventura in the bar.
Otherwise, I'll chalk that up as "Hollywood".
Yet, if they needed better training, I don’t know why that would be a problem? If the squad was green or were making tactical mistakes, what would be the problem with him helping out? Maybe he had better instincts for that sort of thing. And thanks for your service!