Just to prove how unobservant I am. Was just at my local gas station where I found two machines side-by-side. One a narrow cash dispensing ATM property of bank ''Yellow', the other wider one a CDM (Deposit) ATM property of bank 'Blue'
The 'finder' in the OP story, if standing at the cash dispensing machine of his location would be able to see into the hopper of an adjacent CDM. This doesn't explain why the cash depositor thought the CDM had taken his money. No mention of a receipt which he certainly should have requested during his input.
Alas, most of us rich farangs, worship the dispensing machines and never have any cash left to donate to CDMs charities. ????