If they invited the "deleted" elder to give the closing prayer at the end of the meeting, that was a signal to the congregation that "yeah, he's not an elder any more, but he's still a decent chap".
That's the practice I've seen as well. My take was always that if someone decided that he either didn't want to be an elder or maybe couldn't for whatever reason, he should be allowed to step aside with some dignity. The offical WTS position doesn't allow the BOE or congregation collectively to thank them for their service but its basic common courtesy to do so. So this is a way to send a signal to the congregation that the person stepped down on his own.
Crazy and similar to the mob. You can't just quit (that's what my old COBOE/PO said to me when I resigned)