I think we should read Mr Paul’s recollection of events with a degree of skepticism, given he proved to be a less than reliable witness. I also think it’s worth saying it’s not certain in what order George visited HAFAD and Traffic Cars on the Wednesday. If for instance he visited HAFAD first and was told he was wearing a yellow t-shirt, then I don’t find it strange that he’d then ask Mr Paul if he remembered him wearing a yellow t-shirt. The truth is we don’t know how all of this played out.
As far as alibi construction goes though, none of this strikes me as remotely smart or sophisticated. It’s odd and clunky behaviour - entirely in keeping with everything we know about Barry George. Multiple people far more learned than I all reached the same conclusions regarding George’s personality and intelligence - his IQ of 76, BC notes (page 252), “placed him, in the words of one report, 'on the borderline of intellectual functioning'; his memory was very poor, as were his concentration and his ability to plan and execute complex actions; he was emotionally volatile and inclined to become rigid and stubborn in the face of difficulties, and he was also prone to exaggerating”.
Nothing I see in his behaviour that week makes me think George was far smarter than believed. If he *had* killed Jill and possessed a modicum of sense, he’d simply have returned to his flat and lain low. On the contrary, George repeatedly drew attention to himself and raised eyebrows - entirely consistent with how he’d behave on the regular, and also completely at odds with how Jill’s killer apparently behaved.