Was playing on Xmage, used animate dead to steal an enemies dead Sidisi, Undead Vizier. Exploited Sidisi with Sidisi, but my enemy, his owner & not controller, got the exploit tutor trigger. Is that actually supposed to happen? Or does the tutor trigger for its controller and this is a bug?
The Exploit triggers will occur for, and be controlled by, Sidisi's controller when she enters the battlefield. Since you controlled her when she triggered, you get to sacrifice a creature (which seems like it worked) and then, since you Exploited a creature, you get to search off her ability.
It sounds like a bug.