When you're descending at a rate suitable for human cargo in good weather there's plenty of room to maneuver.
A C-5 that's trying to drop out of the sky ASAP before anyone can shoot at it is a different story.
The pilot and copilot were clearly in WTF mode since there were planes on what they thought was the runway. If nobody had spoken up it would likely have gone back and fourth between them and the tower a few times ("are you sure the runway is clear?") and in all likelihood they would have caught it. If they didn't the pilots would have likely requested to go around. Backing off of what you're doing and assessing the situation when anything is not quite right is SOP in every facet of aviation.
A C-5 that's trying to drop out of the sky ASAP before anyone can shoot at it is a different story.
The pilot and copilot were clearly in WTF mode since there were planes on what they thought was the runway. If nobody had spoken up it would likely have gone back and fourth between them and the tower a few times ("are you sure the runway is clear?") and in all likelihood they would have caught it. If they didn't the pilots would have likely requested to go around. Backing off of what you're doing and assessing the situation when anything is not quite right is SOP in every facet of aviation.