Coincidentally, I just came across that episode (as well as the tornadoes one) in the course of transferring my old videos to DVD. Apart from it not being at Wimbledon, as (Mr_Data pointed out earlier) that Jimmy Connors lightning strike has to be fake, surely? First off, there's no mention of it elsewhere on the internet, and secondly wouldn't there have been a more violent effect on Connors, physically and psychologicaly, especially as I think he was using a metal racquet ahead of most other players at the time. Wouldn't the game have been abandoned straight away? Again, no mention on the internet.
I have a vague memory that there might have been a storm during the match and that there was a nearby strike and practically simultaneous crack of thunder, and Connors deliberately let go of his racquet out of self-preservation as an instantaneous reaction to that.