Its worse on a TDi due to lack of space. Cost me £45 at the dealers last year to have the pipe reconnected in 3 places.
I don't know how it would be possible to reconnect it if there was less space - I couldn't get under the ABS block at all as it is.
If it goes again and get some tubing and connectors and reroute it so that it's more accessible.
Ours had popped out in the rear quarter panel too. Really odd that they go in multiple places - it has tons of anti-freeze and it's hard to imagine that the tube freezing would move enough for it to come apart. I suppose if the jet was frozen then it might pop off each connector as the pressure worked back to the motor - but that's a bit random.
One wierd thing on our car was the jet was pointing 180 degrees the wrong way. I was baffled for a moment until I realised that it just twisted around. Can't imagine how it got like that and it's normally covered.