Deal with it.
They were being excessively disruptive. Hovering, very closely, with very loud shutters (which on most DSLRs can be muted), and for longer than necessary to collect the desired photos.
The minister has the right to refuse to officiate a spiritual and religious contract if he finds that the parties involved are not participating appropriately. Moreover, he has a moral responsibility to refuse.
1) Not all ministers are paid for the services – in fact, in many circles it’s a rare occurrence.
2) The photographers can do the rest of their job throughout the remaining 6-9 hours of festivities.
3) The minister is not merely providing a service. He is conducting a ceremony for which he recognizes an eternal burden.
4) Many ministers are wisely setting arrangements in early stages dictating exactly where photographers may stand during ceremonies – if they’re permitted during the actual ceremony itself at all. Should this have been done beforehand? Yes. Should he blamed for not having previously imagined that photographers would be so rude that they would hover 1-2 feet behind his head with unmuted cameras? No.
5) Does he retain the right to refuse to participate in a religious ceremony that violates his conscience? Yes.
If you have a religious ceremony rather than a secular ceremony, the religious leader runs the show. In Christian weddings, the couple to be married are not purchasers of a service, they are petitioners of and participants in a service. The minister was correct; the photographers were atrociously rude.