I think I witnessed what I saw as "time travel" lag in World of Warcraft last week when my ISP suffered a fault with my broadband, and I was so desperate to get back online, I decided to burrow my neighbour's connection, for a small fee. It was okay for the most part, with occasional lag hiccups every now and then, until I got more than I bargained for in one match...
So we were doing some 3v3 "arena" or tourny style action, when I suddenly noticed I kind of lagged out. Expecting a disconnect and shouting "omfg" IRL, my team mates saw me as moonwalking on the spot like MJ due to the lag, and to my surprise, I was able to get back into the action 10 seconds after... but in a rather unusual way. Specifically, when the momentarily lagspike ran its course, I saw characters fly over the screen, missiles and objects all over the place at insane speeds, as if someone was doing speed hacks. Then, all of a sudden, it happened again, and this time, I was dead.
I will never forget the day where I experienced "time travell-like" lag. It was embarrassing yet hilarious at the same time - everyone saw me making "teleport" like movements when I did managed to get a few seconds in the game, and all of a sudden, I just hit the ground.