Question #2: Official error during play

[MJT]

Originally posted by ljudge
Here's my weekly post. Again, it's a kicking game question with an officiating error. How would you handle?

K's ball 4th and 10 from K's 20. K punts the ball to midfield. During the kick R signals for an invalid fair catch and ultimately recovers the ball at his own 45. The back judge and line judge forget to whistle the play dead. R advances for a TD. During the run R clips a team K player at K's 40 and then during the advance team K's coach is on the field screaming at the officials for letting the play advance.

I agree as mentioned above, the ball was dead, by rule, even though the whistle did not blow.
Now if have a different take on the rest. Can we not pick up the clip since the ball was dead??? I am giving the coach A TON of leway since WE messed up pretty big. Unless he is past the numbers, or cursing loudly and personally, I would probably not flag him. If he is only out on the field a few yards, I would go explain what happened, and have no flag.
I would be inclined to only have the invalid fair catch foul be called and enforced. Your opinions on my take!?