Yes you are wrong, and what's more you are well aware of it.
The Socialist Party left the Socialist Alliance in December 2001, only after the SWP had converted it into a front entirely under their ownership and control. The SP argued at the time that the Socialist Alliance had no future as a front and that its other affiliates and members would soon find themselves outside it. Which was, I think you'll agree a prediction borne out entirely by events.
The Socialist Party had also made it clear in advance of the December conference that it would stay in the Socialist Alliance if the conference decided on any constitution or amended constitution for the alliance which preserved its federal nature or provided democratic guarantees for minority groupings. The SWP (along with its pliant auxilliary the ISG) mobilised to vote through its own option and to vote down any amendment which would limit their control of the alliance. At that stage, and at that stage only, the Socialist Party left.
As an aside, one of the more amusing things about Respect currently is that seven or eight years of constant bootlicking seems to have done the ISG no good at all. Now that they aren't useful to the SWP, they are treated as an irritant to be trampled on. All that work, all that unprincipled behaviour, and what do they have to show for it?