Is he billing her for the one hour he was present, or for the entire day he took off? Either is rude, but the second would be really outrageous.
I just re-read the original post and see it is the latter. Does the rest of the church know this person is doing this? I have to say that, in my church, something like this would be taken very seriously. If it happened to me in my church, I would take it to my pastor and see what he said.
Although I usually agree with Zip

, this time I would have to disagree. I would probably ignore the bill, and if the person had the gall to bring it up in person, I might possibly pay for the one hour he was actually there, making it clear from my exquisitely polite incredulity that no one else asked to be paid for their kindness. Of course, sending out thank-you notes to everyone who helped should be done as soon as possible.
I'm assuming that this family, being young and with a new baby, needed the help moving because it would have been difficult financially for them to pay movers, and a cross-town move isn't too hard for friends to help out. The idea that someone would charge for this service is simply outrageous.
edited because I didn't read thoroughly...sorry...