Now no longer in immediate threat from Lara, I finally ended the Synchro mode between myself and BB, allowing my Artificial Intelligence to come out of its combat trance at last.
Part of me couldn't believe that BB was still insulting me after everything we had been through, but to be honest I kind of had to accept his point. Lara seemed to shrug almost everything I did off, and even the attacks that physically moved her didn't do any damage.
I had the distinct feeling that she had been toying with me the entire time, and hadn't actually gotten serious until the moment it looked like I might actually escape.
That had been a mistake on her part.