That's simply not true, it's an Edinburgh bank through and through. The fact it bought Nat West does not matter.
RBS was subject to London banking regulations, not anything from Edinburgh. And most of RBS' losses were from operations carried out in London not Edinburgh.
Who is to say that the Edinburgh banking regs would have been as profligate if Scotland had been independent in 2000?
Also, by international convention, when banks which operate in more than one country get into trouble, the bailout is shared in proportion to the area of activities of those banks, and therefore it’s shared between several countries.
Roughly speaking 80% of RBS' operations are in England and 10% are in Scotland, the result being, by that convention, therefore, that the rest of the UK would have to carry 80% of the liabilities of RBS and Scotland 10%.