Meaning of mixed conditional in Hobbit

Greetings!

I've noticed a mixed conditional usage in the Hobbit by Tolkien, which I can hardly understand:

"The most that can be said for the dwarves is this: they intended to pay Bilbo really handsomely for his services; they had brought him to do a nasty job for them, and they did not mind the poor little fellow doing it if he would; but they would all have done their best to get him out of trouble, if he got into it."

As far as I understand, present unreal conditional is more likely to use here: If he got into trouble, they would do there best to get him out of it.

So what for mixed conditional was used here?