Jim ran. The zombies followed. A few yards after, Jim saw an open dumpster and was met with two options. Hide in the dumpster, or use it to vault over the school wall. Option one meant he'll be trapping himself, only waiting for zombies to mob him. Option two means he'll be trapping himself [i]inside the school[/i], not knowing what awaits on the other side. He chose option two, hoping there were no zombies behind the wall.

Jim used the momentum to jump towards the dumpster and propel himself from it to vault over the school wall.

There were no zombies, but a nearby building burned.

He quickly removed his white coat to use it to counter the flames as he went in to check for people who needed help. He expected someone who needed rescuing from the fire, but what he saw was revolting. 

Jim was at a corner two meters behind a man who stood over a bleeding...boy?Girl? Jim was confused, but it did not matter now. He had to help.

Jim, being skilled in stealth sneaked behind the seemingly insane man. He then used an attack he learned when he was training to be an assassin. A knock out punch, a quick blow to the side of the neck, perfect to temporarily disable guards, or in this case, hostiles that didn't need to be killed.

Jim was confident in his skills, but he still rushed to save the person, ignoring whether the man fell or not. He carried the person away from the man and looked for a safe place, even though there were no more safe places left.