I've noticed that a fair few of the P567s around Bournemouth have tape holding the bowl to the canopy. I always thought these were quite sturdy lanterns, but an example in my town has been hanging open too, so maybe the clip is a weak point? Or maybe it is just crews being too rough when it comes to lamp change. As the lantern only has one bowl clip, I guess if this, or the part of the bowl becomes damaged, there is nothing else to act as support.
However, the P567 should have clip pieces which hold the bowl hinges in place meaning it won't be possible for the bowl to fall completely from the lantern (if they are attached), meaning the bowl can easily be fixed one way or another when noticed. Quite clever really!The P567 doesn't have the best of build quality, and after 20 years on the road are a bit ropey! The bowl clip is only plastic and this simply wedges over the lip of the bowl. They have the tendency to try to undo themselves and even as you clip it shut you can feel it springing open again! Not surprised you've seen tape employed