Those clinicians did that because they are unlawfully discriminating against someone with mental illness.
And because UK funding for mental illness is so piss-poor there's not much service for those doctors to refer into.
The lack of funding is a political choice, it's got nothing to do with the socialised nature of funding.
I was trying to think of explanations for the apparent callous nature of the emergency doctor who tried to discharge him from A&E and the nurses who gave equally brusk treatment. The first thing that came to mind was that they treated him effectively as a self-inflicted "slow" suicide case and it must be some ethical resource allocation issue. ie. hypothetically "Why am I treating this self-inflicted injury when there's a kid in the next ward who's been hit by a car and needs 24/7 monitoring"