My apologoies on bumping an older thread, but there is a lot of mis-information going on here, and hopefully, the matter can be put to rest.
First, as far as WHEN this was happening, it is probably around 1994. Obviously Bret and Owen were feuding, and you can hear Gorilla Monsoon calling the match. I'm guessing somewhere between WM 10 and SS 94.
Finally, as far as the "title reign" goes, this video does not do the scene justice. If you do your research, what you will find is that after the video ends, the match gets re-started, due to the interference at the end. Bret Hart goes on to win the match.
Thus Owen Hart NEVER WON THE WWF TITLE, as the original decision was overturned, and the match was restarted. Thus, it was never recorded as a match win, and never recognized as a title win.