Better to be safe than sorry, i got a right bollocking off Mrs Tea the first time mine came out of the airlock onto the kitchen worktop
About ten years ago, when I first got back into home brewing, I made up some demijohns of wine. One of them had lots of elderberry pulp in it.
Anyway, after I had put them in the spare room, I set off for a weekend away in Nottingham painting the town red. Whilst I was there, I spent an unspeakable amount of money on a Paul Smith shirt to go out boogieing in, proper dandy I looked (I was single at the time. Well, sort of). I arrived home, hungover, back to sunny Lincolnshire and walked into my cottage. I could hear a faint 'sssssssssssssss' sound like gas escaping, but thought nothing of it. One of the demijohns appeared to have stopped fermenting as the airlock showed no activity. Sssssssssssss. So I thought I'd go and have a look. Sssssssssssssssssssss. Interestingly, it also appeared to have overflowed bright pink pulpy yeasty gunk and, sssssssssssssssssssssssssss, filled and blocked the airlock and, sssssssssssss....... BANG! The bung came flying out of the demijohn, spraying bright pink gunk all over my face, the walls, the ceiling and (you've guessed it) my newly ruined bloomin expensive shirt.
Given that the gas had no means of escape, I should really count myself lucky the whole thing didn't explode and kill me with shards of glass.
Still, something to keep an eye on if you get very vigorous fermentation with pulpy juice!