I've actually seen almost the exact same thing happen in a wedding - the pastor stopped and asked that no flash photography be used during the service (not quite this nasty about it). He did have a conversation with the hired fauxtographer (yes, used intentionally) prior to the service, which they openly and repeatedly disregarded during the service.
If you use clergy to do the wedding, I assure you that the pictures are NOT their first priority - no matter how important they are to you or the bride and groom. Some are more flexible than others, but the ceremony is about the vows and blessing of the marriage. Period.
Yes, there are exceptions. Yes, some of you will disagree and get pissy. Too bad. Having been in church work, I can tell you - that's just the way it is.
We just don't know enough about this situation to make a judgment either way.