That's odd. I recall the briefing about PN being bought by BT didn't happen until late 2008. There was no sniff of a take over for most of late 2007 into about Setpember 2008.
Maybe my memory is not in tune with wikipedia, a website that can be edited by anyone and therefore is 100% accurate, vs. my own experience of being staff there at the time!?
I couldn't possibly comment about the state of your memory, but if Wikipedia has it wrong, then it is one amongst many.
Industry websites seem to agree - eg telecoms.com, the register, the panel on takeovers and mergers, and the FT.
Even Plusnet's user group forum talks about the dismissal of Lee Strafford in March 2007.
The best thing, of course, is to rely on the horse's mouth: