For the party I DM for, one of the Minotaur players has an nearly absurd (judgement call) feat called Opportunity Gore. Opportunity Gore lets a Minotaur use his racial power Goring Charge over and over again as an opportunity attack.
When Goring Charge hits, it knocks the target prone. So this leads to a slew of questions about how proning affects a creature in mid-movement. I think there are some rules for this situation but I can't remember where they are.
The primary question is: Does an opportunity proning immediately end movement and the move action in the triggering start square?
If not, what would happen?