Yes, you're correct of course, the poor OP was 3mins late - I hope he hadn't been delayed in the queue. Unless, of course, that the website has been updated very recently.
If the OP (who presumably is now in RUH) is still in contact, it might be an idea for him to check any onward or return sectors on the original booking, as they may well have been cancelled if he was considered a no-show on the outward leg that he was prevented from boarding.
In my day it was all very different.........180secs! Unless of course we were overbooked.