There has been a lot of misinformation spread about this that the killer was a Syrian refugee - there were quite a few proportionally placed on the Scottish Isles including Bute. Naming the killer has at least dispelled that myth.
His name was out there on Twitter etc for anyone that was looking anyway.
Ah that makes sense then.
I guess the Judge looks at the 'lesser of the two evils' effectively, and like you alluded to, in this case it was more important to destroy the myth of a 'foreign perpetrator' (which could lead to social disharmony/racism) rather than follow the usual case protocols.
Nice to see we have Judges that think in those ways. Justice with wisdom. For the greater good etc.