Cull neophyte bug

I sniped an Overgrowth on my turn 4 with cull neophyte, but the druid top deck’d overgrowth and can use the spell, with his 4 mana and my cull neophyte battlecry completely off. I’m not too dumb to not understand what “every enemy spell on next turn cost 1 more” thats a bug, if you top deck the spell dont have the debuff

Did your opponent play Nature Studies previously?

lol bro, yes, i never knew that xD