Guild Wars 2

Just want to report a invulnerability spot as you can see from the picture.

First I have seen of this one. However, there is also one in Bordlands SW camp as well.

Well…is this “hiding spot” regarded as an exploit? Some people use it to protect themselfes; they are just staying there and do not attack enemies. Some use it as a shelter when they are almost down.

I think you answered your own question there. If you just stayed there, not attacking anybody (basically you are just taking a short afk break) you are merely a distraction or bait. Those are borderline cases unless you consciously acted as bait.
But if you used such a safe spot as a shelter against certain defeat or to launch attacks without fear of retaliation you exploit a bugged game mechanic to your advantage and rightfully deserve your Report for “cheating/exploiting”, an option we desperately need for those cases.

I saw this too and there was a group of players who were just sitting there attacking players from our server. They sat there teasing us for maybe 10-15 minutes, while their server’s other players went around taking our other resource nodes. They would run down the hill to bait us, then run up the hill and shoot at us. I put up my projectile reflect spell up and that seemed to damage them sometimes, but everything else would return “invulnerable”. One particular guild had multiple members camping here at one point, and one particular player was spotted roaming around this spot for hours. I’d say that’s exploiting.

Sitting in the spot to avoid taking damage is an exploit.