Just thinking along the same lines as the comment I read in the New Statesman
The story of the night, though, is the demise of Scottish Labour, which put in its worst ever performance in Scotland, it’s the party’s worst result since universal suffrage was introduced in 1928. The party’s vote share was down across Scotland, and the results are sufficiently poor that they could see them fall behind the Conservatives to become the third party north of the border
This from a party which has dominated Scottish politics ,mcertainly in my lifetime.
I'd consider that a "rout".
What would you call it? An acceptable setback? An electoral hiccup?