You normally don't think of privacy with restaurant bills, but the pastor's signature was posted on-line. I don't think I'd care for that either.

I think a warning should have been enough in this case. Firing was extreme if this was a first offense.

Was the pastor basically saying that 18% was too high, and trying to use tithing as a comparison? I didn't read that the pastor was claiming religious exemption, just disputing the rate. A cash tip was left on the table, apparently. However, the 18% is a known surcharge (I don't call mandatory rates to be "tips"), so the pastor shouldn't have ordered if the 18% was a concern.

So, I think I just said that all of them are in the wrong here but I would say the waitress is most wrong for invasion of privacy.