An inventory can be duped by cuffing a player who just logged out, taking their gear, then uncuffing them before their entity leaves the world.
- Legacy ID
This method requires at least 2 people, but would be easier to preform with 3.
Character A is the inventory to dupe
Character B is a player wearing nothing at all
Character C is a player who has both hand cuffs and a handcuff key
- Have A log out of the game
- Once A has left C puts the hand cuffs onto A's log out entity
- Character B then accesses A's inventory and moves all the gear to his own
- Once B has taken all the gear, or about 15 seconds have passed; C uncuffs A
I theorized the other day that character data is saved when the player exits the game, and not when their combat-log entity leaves the world.
Originally I tried cuffing the player and grabbing some gear, but did not uncuff the player before his entity was removed. This resulted in him spawning as a new character the next time he joined(The combat-log entity was removed from the world and never created a corpse; there are other reports about this)
On the second test we had a third member handle cuffing and uncuffing; We were successfully able to take the entire inventory of the member this way, and have him spawn with all his gear in tack; duping it.
This method of duping will continue to work for a long time, unless character saving happens after the combat-log entity is removed; or you remove the ability to cuff a logged out player.
As a note to this; I've witnessed a friends combat log entity accidentally get shot by another member in our group right before we were all about to log out. His entity's shirt was visually ruined and was bleeding from his arm, He was at full health before he logged out so there was little chance of his entity passing out from the shot let alone dieing. We had the member rejoin the server shortly after; His shirt was pristine and he was not bleeding.
The situation just described falls under the same mechanics as what is outlined in the OP. If this is an intended mechanic of the combat log entity; Consider this when solving the OP.