Honestly, is it Edmunds fault he was out of position or the coaches? With the way the Bills fell apart in half #2, I lean towards blaming the coaches.
I could be wrong, but the Rams had way too easy of a time scoring in half #2.
I wouldn't be surprised if Edmunds poor play was a symptom of a bigger problem, that McVay exposed. That said, Edmunds did have a poor game (I agree with you on that).