Looks like BG Fortris CU with what look like type A RCD’s looking at the symbol under what looks like a 50p shape, so thats fine from that perspective.
At a guess, I would imaging the EV charger was initially supplied from the Henley blocks, so at that time would have been a seperate circuit and nothing to do with the 16A circuit that tripped, which, as you suggest is too low an Amperage, especially whent the diswasher is on heating cycle. Don’t see why he pushed a new CU, when it would have been a simple changeof MCB, but hey ho not to worry.
I think the next port of call is getting Ohme to attend due to a burning smell when in the cupboard when charging the car, whils’t making them well aware the house electrics have been fully tested and a new CU fitted by a qualified electrician. I wouldn’t mention the MCB tripping, as that is a seperate issue and not to confuse them.
I would tell also tell Ohme, you expect it to treated as an an emergency, as a matter of safety.
We shall speak later in the week, unless you have any questions in the mean time 🙂