So, I've had a Helles lagering in my fridge for about 2.5 weeks now, and I just noticed that the airlock was knocked off by someone putting beer on top of the fermenter. I'm guessing this occurred last Tuesday when we ran out of room in the fridge. It hasn't really been fermenting since then, so I'm wondering if the beer got oxidized over the past 6 days. The fridge is sitting around 45 degrees. Any help would be appreciated.