wanted to pick up a molotov. had to get real close to it to not pick up the gun next to it. Finally got it to say "press F to pick up Molotov", it picked up the gun next to it...
Wanted to close a door, instead I picked up the gun right in front of the door and lost my original gun in the mess.
I've also come across this problem where it highlights an item to pick up, but I seem to grab whatever object is actually closer to my player. Fortunately this isn't during combat, but then again you never know if an enemy is close by so eventually this will cause a bogus death. Honestly this is one of my only problems with this game.