Hard to say what is going on.

Camouflaged Rambo wanna-be outlaw fondling a gun in the woods stumbles into a couple of hikers and fires a shot to impress them. Feeling embarrassed, perhaps running from the law, he figures he will tie them up to give himself time to get away. He flees. They get away. Authorities show up. Could be.

Or maybe a bored couple come up with a story about a armed man who ties them up hoping to gain some notoriety and press.

Not enough information to say for sure what happened.

Good news is that no matter what happened nobody seemed to get seriously hurt.