Truth in the face of a stinker?

Lately I've been wondering... What do you do when a co-worker at your church gives a rubbish sermon?

Not just a dull sermon, or an averagely presented sermon, but a outrageously crap drivel.

I'm torn, because I've been in the situation before and (almost certainly) placed others in the predicament.

I want to say that you tell them the truth. They could/should have done better... They tried to be too creative and lost everyone... They didn't connect with the audience... They offered a dry, dull, monotonous diatribe... They were just plain wrong in what they said.

I want to take a hard line because the results effect the church.

A rubbish sermon may turn those away who are church-shopping. Similarly, those who are turning to the church for answers will continue searching elsewhere once confronted with a non-scenically ramble.

Then again, there could be extenuation circumstances that contributed to the poor showing and maybe grace should be shown...

I don't always hit it out of the park...