Oh FFS its not complicated
BAE probably operate the Talk Talk B2B product security monitoring, probably via some offshoring tentacle.
BAE (ex-Detica) were probably brought in after the hack to advise on beefing up security on the Consumer side of the business.
2 different divisions of BAE, 2 different Talk talk products - their BAU/Production Services arm vs their high end consulting.
As for the B2B guys who got hit - I saw in the Reg comments a lot of the smaller businesses were moved onto the Consumer product.
Do keep up El Reg & Commentards.
Doesn't change the fact that Talk Talk have failed everyone badly.