The PA man can

Above all, make friends with your PA man (or woman)

Okay, this is the house of God, but they could have had an argument with the spouse, or worse, the pastor's wife or church secretary.  They could have had 2 hours sleep or less due to some ailment or crisis, the equipment may be playing up and it hasn't had a service since Blair's first term, their car could have broken down and they arrived an hour late, you could have given them the wrong SOF numbers....(erhem)...

You get the picture.  They are human.  Tip them over the edge and you may just find that they can quite easily turn you off completely or make you sound like a wailing cat in a snowstorm.

Actually, I have a very good relationship with our PA man, and I haven't managed to naff him off yet.  I don't intend to.