lol, connection lost during singleplayer blitz

So...
I upgraded 3 laser turrets in a row really quickly and at the same time I killed a scrambler. Than out of nowhere I got dropped for losing connection to the host. I was playing singleplayer sudden death blitz. Can you disable the option that internet is needed in singleplayer? Because, I still have internet and maybe it just dropped for like a half second.

If your steam drops connection then you get that message too.

How lame My internet never drops in any game, maybe on rare occasions a half second drop, but this is a singleplayer mode, can't they remove the internet check on singleplayer modes?