But aren't we all breaking the same law when charging via a non-EV dedicated 13amp socket using the UMC? I've never quite got my head around why it's OK to use the UMC with a 13amp socket yet if we plug in via a commando socket we have to meet all the regs.
Just to clarify, the law relates to the installation, rather than the usage, plus the regulations that apply to an installation are different to the regulations that apply to appliances. This means that a user of an appliance (the UMC in this case) is not required to comply with any regulations, they just have to use a bit of common sense, i.e. not leave the exposed 13 A plug out in the rain, for example.
If a weatherproof 13 A outlet is installed outside, then it has to be RCD protected, and has been for years, because there's long been recognition that the probability of getting an electric shock from anything plugged in outdoors is significantly higher than from something plugged in indoors.
Intention. If the commando was installed to use a table saw but you used it to charge the car I guess it would be... ok? Just like the 13A sockets were not installed to charge the car?
Following on from the above, it comes down to whether or not the installer believes that the purpose of an outlet is to charge an EV. If the installer believes, or suspects, that any outlet is to be used for EV charging (i.e. the customer has an EV and has asked for an outlet to be installed close to where they park their car) then the installer is obliged to install it in accordance with Section 722 of the regs. In the case of outdoor commando outlets, they usually end up being installed with open PEN protection and an RCD anyway, as nine times out of ten in a domestic scenario they are used for things that require this, like running power to a caravan, and there has always been a requirement for such an outlet to be protected like this.
I believe [cannot remember the source] that the regulations may relate to devices only over 10A. So UMC and '13A' plug may be outside this. Obviously safety still applies at any current.
As above, the difference is between an appliance (in this case the UMC) and an installation (an outlet intended for EV charging, such as a commando or a charge point).
The intention behind allowing the UMC to be used, without the same level of protection as a charge point, is really because the UMC isn't intended to be a permanent, everyday, charging solution. The UMC is about as safe as an appliance can be, and does have integral DC sensitive RCD protection, but that RCD protection doesn't comply with the standard required for an installation (as it's not installed equipment) and also the UMC cannot provide protection from an open PEN fault. I believe the assumption is that, as the UMC is unlikely to be used as an everyday charger, and as it's a very useful "get out of jail" charging method, the risk posed by not having open PEN protection is acceptable. Given that there are loads of charge points installed without open PEN protection, because some installers just haven't bothered to fit it, it's probably a reasonable view.