I don't know if someone else has noticed this, but in recent Fort matches it happened that the WF gets nuked on it's roof while the mines on the stairs are all intact.
So today I saw a parachute next to the WF stairs for 1 second or so. I didn't think much of it, maybe some teammate jumped off the WF roof, so I went on.
One minute later a nuke gets planted on WF and guess what, an SBH was sitting on the roof and guarded his nuke. Again, the stairs mines were all intact.
The obvious conclusion is : You can glitch on the hill right next to the WF, jump, and land on the stairs with the mines behind you, nuke the roof and nobody thinks it's up there because the stairs are still mined.
This is kind of a major glitch because Fort matches can end pretty quickly once one team loses it's WF/Airstrip.