My understanding is that a Tantri is not a regular priest of a temple ; He will do special poojas and rituals during festivals. Normally in other temples the Melsanthi is the regular priest. A Tantri will be so busy that he will not take note of who is entering the temple. It is the temple authorities who inform the Tantri about a Christian entering to the temple and such issues.
In future the Tantri can let the temple authorities decide who is Christian and Who is non Hindu. Tantri should seek get a written complaint from temple authorities that a christian has entered the temple and punyaha is needed
All caste related issues general public will put blame on Brahmins. So Brahmins must play diplomacy and avoid such controversies. The truth is now caste based discrimination is done not by Brahmins but by other communities (for inst the Gujjar-Meena problem) but still Brahmins are always blamed. Thats the general norm.
Brahmins don't give chance for others to blame you. Play wise. Time demands that
