Harassment and raid lockouts.

So I'm having issues with a player in game. He was a pugged member of an Ulduar raid, and he turned out to not be very good. We got to Yogg, but then called it and I rescheduled the continuation for this Monday, without him on the invite. Today, in trade, I see him advertising for a Yogg kill (using the same raid ID/extension).

I asked him not to, because I planned on picking it up, he called me names, etc. I reported him and he began harassing us. I camped out in Ulduar so he couldn't take his group in and down bosses- he repeatedly pulled Yogg and killed us, for amusement/harassment.

I'm concerned that he 1. will camp out a group in the instance while I'm asleep and that will lock out my group tomorrow, or 2. that he will be able to extend the same lockout with us on it.

Is that possible? Could he extend the lockout without my consent/permission? Is there anything I can do to ensure that my raid is safe until our scheduled raid tomorrow, besides camp out inside?