One would not expect an exit node to be used for cp. A relay node would be more likely used for cp as one would expect the request to be internal to the tor network. A tor exit node is only used to access sites on the regular internet, not the “dark net”

if you join the tor network other tor users proxy their trafic through a chain of tor users and therefore maybe though you, sometimes youre the exit node that then actually sends the request to the server in question, sometimes you just pass it on to another tor user.

so the person in the OP did technically send the reques to the server that served CP, but he didnt really have anything to do with it nor could he have even accessed the data.

AFAIK you should never run one on your personal IP

Edit, wasn’t a personal IP. I mistook it when I read his apartment got raided. Advice still stands tho.