No, hot rookie goalies never have a good sophomore season. Next year, or the year after, he'll be dynamite. You just can't pressure him too much or else you wind up with a Price or Raycroft.
It's definitely starting to look like a fluke. Yes, he's not getting a lot of help from his defense, but he's been letting in some awful goals lately. His rebound control and puck handling have been atrocious as well.
Stat alert: he's been yanked 4 times already this year, he's given up 4 or more goals in 9 out of 22 starts, and he's 0-5 in shootouts (the last against Chicago may not be his fault). More importantly, the team has blown a lot of late leads, showing that he's not been able to make big saves in big situations.
Does this mean he's done? No. Not by a long shot. Even if he never returns to his rookie form he could still be a quality goaltender for years to come. But for now, his team needs wins, which means Matthieu Garon will slowly start to creep into conversation of who should start in Columbus.