The thief was pretty ballsy to pull off that kind of crime where he actually put himself on the path of death. Why would he risk his life for a cellphone? The thief grabbed the phone and escaped to the other side as the train was just a few meters away. The owner of the phone was behind the thief by just a second or two and that's when the train squished him. I wonder if the owner didn't notice the train that was already close by or if the shock of having his phone taken blinded him as he was focused solely on chasing the thief.