This is the reason that I went to the 9 gallon plastic fermentation buckets. I used the blowoff tubes for the longest time, but you soon realize, that the blowoff is taking beer with it too. I didn't like losing a 1/2 gallon of beer each time I had a fermentation go out the blow out tube.
I've never had one go through the airlock on my 9 gallon plastic fermentation buckets.
As far as your beer goes, it is fine. The stuff is coming out, not going in. The only problem is that sometimes the airlock gets blocked and won't let the stuff go out through it, at which point it can build up enough pressure to actually shoot the airlock out of the top of your carboy. If that happens, you end up with not only a mess on the ceiling and carboy and all around the carboy, but now you have an open fermentation, where nasties can get into your fermentating beer.