There is very little to read into this. Rochdale is an unusual constituency, Galloway is an unusually high profile candidate, there was no official Labour or Green candidate. Still, he failed to even win 40% of the vote yesterday.
This sort of thing is his speciality. He's personally won three seats from Labour over the last few decades but never in circumstances that can be repeated by other candidates in other seats. This will be no different.
Also he's a deeply unpleasant individual. It's frustrating that the false charge of antisemitism gets thrown round like confetti by supporters of the Netanyahu regime, because when an actual bonafide antisemite like Galloway comes along people don't realise that this time the shoe does fit. His previous support for Nigel Farage's Brexit Party is total horseshoe theory stuff.