Green’s Dictionary of Slang

(US) a euph. for Jesus Christ!

1978		J. Webb Fields of Fire (1980) 165: I’m gonna die. Oh, Buddhist Priest. I’m only nineteen.
1980		D. Cragg Lex. Militaris 54: Buddhist Priest. A VN war expression used as an exclamation of surprise or disgust. A play on ‘Judas Priest.’.