Maybe you should recon every trail, every time you ride it. Does anyone in the world do that?
OK, obviously unofficial digging, you can hardly hold to official digging standards. Expecting signs etc isn’t realistic. But, they don’t have to be dicks about it either. Some of the local diggers have a real thing for digging holes in the blind behind a jump, sometimes it’s borrow pits but sometimes you see the spoil’s just been tossed aside- the only reason for the hole is to add consequences. (similiarly, throwing debris into the landing area so that if you come up short, you crash) Why would you do that?
So this one sounds a bit like that, digging a hazard for no real reason at all, which is a ****’s trick IMO.