If you have a melee weapon on your back and another in your hand and you eat or drink something, either from inventory or vicinity, once you're done eating/drinking the weapon you held in your hand can be seen both in your hand and in the vicinity. After testing a bit it turns out it's actually only in vicinity and you need to remove it from hand and pick it up again. It is only displayed as being in your hands. This might result in the player thinking it's in their hands and then running off without the actual item.

I have only experienced this with weapons (fire extinguisher on back and cattleprod in hand, sledgehammer on back and machete in hand and so on) and do not know if it applies to other items as well.

Also when testing this I did not have enough space in my inventory for either of the weapons to end up in for example a backpack.