675 Daytona Hyrolocking On Fuel - Why? Anyone?

As per title have a 675 Daytona fuel injected which as of today has hyrolocked with right cylinder fuel of fuel - almost blinded meself after pulling plugs when it cranked over and bounced the fuel off the screen straight back into my mince pies - still stinging hours later.
I am however confused - bike been standing for months, had 10 x fresh litres e5 in tank - started off the button on all 3 cyls then went to 2 & started smoking then cut out (as I thought - but obviously the starter click was it hydrolocking so just hope the rod didnt bend...).
Can anyone explain clearly how that much fuel - and it was a LOT could accumulate in the cylinder, without going out the exhaust port, so fast via the injector to cause this? I understand with carbs & manual fuel taps but not this. This now seems clear to me this was the same problem last year when I decided it was the starter that had gone - took me few weeks to replace and did plugs/oil at same time so any fuel must have drained to sump by then.