This is the standard understanding, and I believe it is mostly true.

However, last year, at the end of a very severe winter, we watched 150 or so deer and 40 or 50 elk grazing on my big hayfield. Three coyotes were spaced out in a line looking up the hill, and there coming up out of a gully were three wolves, just having obliterated a deer.

NONE of the elk, deer or coyotes fled. The ungulates were, we know, exhausted, and many died due to the winter, but the yotes could have split the scene but did not. They just watched the wolves walk away, no doubt unconcerned due to the full bellies.

It was dusk but I put my skis on and tried to find the bastards to take a picture of them, and being 1000 yards behind them had no good chance to catch up, but they split up and in the dark under the starlight between the patches of cloud I cut the track of one on the mountain, and kept at it, but never caught up to it. Hopeless, but I really would have liked to have gotten a good closeup view of them...

I got home late into the night, pretty worn out, but the experience was instructive, and we are little by little being instructed...