Not much margin for error 23 stories up.
Don't you have to have pretty significant airflow just to pull the parachute out of the pack? Then you need more to inflate it... don't you hang like 20' below the canopy also? So that gives you 230-20 = 210 feet. To get going 80 mph you need four seconds, and in four seconds you fall... let's see... 1/2 times 32 * 4 squared... 256 feet.
He needs to fall 26' farther than the height of the building just to get up enough speed to get the parachute to deploy. No wonder he became a pancake.