Speed = dist/time
So Time = dist/speed
Hence @Jerak arrived at the lift door at time = 15/2.5 = 6 seconds.
So the lift doors closed at 5 seconds while @Jerak arrived at 6 seconds, thats why he did not enter the lift.
Also the guy inside the lift standing could also be an asshole since he should have hold for @Jetlack who he clearly saw running to board the lift.
Portfolio: Sold
You know you've made it when you get a parking space for your yatcht.