Clutch pipe

I was driving to work today and was sitting in traffic. All of a sudden I heard a pop and my clutch pedal dropped to the floor. I got the car towed to work where I found the flexi pipe from where the bleed nipple is had popped out. Not I've refitted it and gave the clip a squeeze together for a tighter hold..it's bled out and working ok now. Has this happened anyone else?..is it the sign of a bigger issue?...I only fitted a new 4 piece clutch kit last year but the pedal has given trouble with sticking so I think it could be related. It's an 2006 tfsi vrs.