I wouldn't say riding the coattails. He was funneling Brady the defensive calls for the first three super bowls when Brady didn't even have a 2 to 1 TD to INT ratio.
That doesn't make the case to hire Belichek because it wasn't good coaching, just cheating, but he wasn't riding the coattails. More like working the puppet.
I'll ride or die with McD before following a cheater like that. Character in sports matters.