#4 The other Titus O'Neil moment (WWE Royal Rumble 2015)
No, this isn't the one you were thinking about. This list is only focusing on in-ring botches during Royal Rumble matches. Titus O'Neil's tumble at the Greatest Royal Rumble does not count in that respect, but this moment does.
His elimination from the match in 2015 isn't much talked about, possibly because of what happened three years later. It may be the fact that there was already a lot wrong with the 2015 Royal Rumble Match. O'Neil was likely tasked with matching the record for the shortest time in a Royal Rumble - a near-impossible feat.
The former WWE Tag Team Champion was supposed to be immediately clotheslined out of the ring by Roman Reigns and Dean Ambrose but he did not go over the top rope in time. O'Neil then promptly jumped over by himself and ended his Rumble stay at four seconds.
There were timing issues in that spot, which had to be exactly on the mark. But much like most of the 2015 Royal Rumble Match, it did not come off as well as hoped. A series of booking mishaps in that match culminated in Roman Reigns and The Rock being booed out of the building.