Lol, r u guys for real? This is an old lend item scam. It's not a glitch, just a simple scam that onlys works on unaware players.
When YOU think ur accepting THERE item on second trade screen they decline, thus why there was a recent update of when the other player declines it now says it in red writing for those unaware players.
Then they ask for there item back (which if ur dumb you'll think ur holding there item) and they'll lend the same item.
Very surprised very few of use knew of this