Overflow pipe on tanks will slop diesel on corners as the fluid is force into the pipe. Also, not every lorry/truck/van/bus driver puts the cap back on properly after filling up or after over filling, so diesel slops out. Not nice. I’ve reported a couple of buses for leaving a large trail of diesel behind them through Deptford.
Always good to hear you came out of it ok 
ok tbh looking at your replies (and ty for them) i think i aquaplaned (the place has alot of puddles) and lost it instantly, as i had not even half a second to respond to the aquaplaning what could i have done to save it?
im going into hospital now for my op ill give you guys a post wen i get out with lots of nice grisley pics
Ride safe everyone x
Good luck with it x