Duskblade passive wasted

Whether it is intended or not, I think it sucks when you see a ward that is already revealed by a pink ward or scanner, but yet your duskblade passive still activates and wastes the passive and puts it on cooldown. It's a waste since you already have other sources revealing the ward or invisible trap. Maybe this can be fixed? Just wanted to get this out there.

Also consider one person already reveals a ward with their duskblade, only for your duskblade to activate on the same revealed ward and it wastes your duskblade. I think maybe a good solution might be to just make it that duskblade passive only works on wards and traps that are not revealed?