Ok, I'll evolve.
James death was very similar to the way his life had been, pathetic and quite forgettable. He had been an underachieving, procrastinating, overweight and undisciplined dissapointment of a human being. He had spent his life doing heroic amounts of nothing. So when the neighbors two neglected and desperate for freedom German Shepherds dug out of their kennel and found James they where once again robbed of any real predatory stimulation. James body unleashed a mighty dose of adrenaline, propelling his bulbous form for 6 entire strides of panicky jigglily escape before his heart finally rebelled against the injustice it had been subjected to for the past 27 years of sedentary gluttonous life, and stopped.
It might be that some lingering negative karma from that poor mistreated heart followed James through death itself, in an attempt to make certain that no other heart would ever suffer as it had. Maybe that's why out of all the myriad forms of life in existence, James awoke after his ordeal to find himself in an incredibly alien and disorienting body. James awoke in great confusion, but for reasons he didnt yet understand, with the innate knowledge that he was now a jellyfish.