Is there a reason you don't want to use two separate pools? I think the above iRule is probably simpler than using priority group activation. You might want to explicitly disable persistence for the sorry_pool using persist none. If you're using persistence for the default pool, you'd want to also enable it using the persist command.
You can't kill a different active connection from an iRule which is executing for a different connection. But you could affect which server is selected for the current connection. We discussed a similar scenario in this thread:
http://devcentral.f5.com/Community/GroupDetails/tabid/1082223/asg/50/aft/1178810/showtab/groupforums/Default.aspx
Aaron