hmm this truly is a mystery. How can preventative measures be taken against something that is spontaneous?? Might just have to live with the uncertainty.
Also with such a huge flash, Blackpool being 250+ miles from you and all, how come you've not mentioned damage to your pants or even men's bits and bobs?
I wonder if you could make a warranty claim, mind you it seems your local dealer is quite familiar with this so might be difficult to argue.
Be careful what you wish for...