Desynced

[EbToxX]

I was playing a game in RGC pub and i pressed alt tab to replay the song i was listening to and when i got back in the game the RGC bot just reconnected me back because i propably lagged when i pressed Alt Tab,but the problem is that when i got back in the game i was 20 seconds ahead of the other players and i ended playing on my "own" game and ruining the game of my mates.
Any Idea why did this happen?
Here's the replay...
http://www.adotaparser.com/dota-replay/274449