i know it isnt absolute evidence of the same thing but your experience makes me suspect it was.
i played the Archivist in the situation where the opponent had 5 bombs in my deck. I played her. The opponent puts one more bomb in my deck. My turn a bomb hits me for 5 damage. Either a 1 in 11 chance and he got lucky or it could be the other 5 bombs were still there… just like your circumstance