let it ride man. i use a plastic bung to go inside the mouth of the carboy and then put the airlock directly into it. the yeast obviously had a field day on your wort. is it a high gravity recipe?
this happened to me with a plastic bucket and an airlock. i had a little too much wort and thought it would be ok to overfill the bucket a little bit. had very hungry 1056 smack pack swelling for 24 hours and i threw a pound of belgian candi sugar in the boil so the wort was very sweet. in 3 days i noticed that there was a bunch of brown stuff in the airlock and it looked like my bucket was ready to explode. it was the krausen actually pushing its way up the airlock, down the bucket, and it jammed the airlock and almost popped its top.
i'm thinking the same thing happened to you. only in your case, you used a carboy. what i think is that your orange plastic cap spit krausen down your carboy.
my beer tastes awesome- i was initially concerned about a bug getting in it since it was exposed to the water in the airlock but it doesn't have any off flavors. i think once there is alcohol and hops and carbon dioxide in your wort, it's hard for other things to survive in there.