Brundle said that Lewis had more-or-less matched Nico and the official timing supports that case rather than this five tenths.
So which was it, more or less?
You don't complete a lap it's aborted, no time is recorded until you cross the start finish as part of a lap. Why announcers looking at the F1 sector feeds make something like that up? I don't know, maybe they were lying? Maybe Lewis blew his wad in Q2 and wasn't going to beat him in Q3, I mean Nico has a history of beating Lewis to pole position right?
Maybe I'm just reading it wrong, but the tone of that seems somewhat childish.
Anyway, to address the actual point, I don't know why they said what they said - I wasn't listening to them, and I wasn't there with them. Lewis' final lap time
was recorded in the FIA timing documents, so there is no reason that the sector times from this lap wouldn't be. In addition, we've seen in past qualifying events where a team has only been doing one flying lap, they will initially go out and just record a few sector times on old tyres without completing a lap, to give them something to fall back on. Now, maybe there's a chance that you're right and it hasn't been recorded, but personally I don't think that's the case and I believe that this plus time was relative to his own PB. I guess unless we can actually find someone with a full breakdown, we'll never be 100% sure one way or another.
What I find strange though is that we know Hamilton is fiercely competitive and will push the limits. If he was two tenths (or more, as some apparently have said) up on the pole time in the first sector, then I would expect him to do the very minimum required to count as lifting in that corner, before pushing on with his lap. He'd have had a few tenths advantage from S1, had been the faster Mercedes driver in S2 pretty much all weekend, and would have a very good shot at snatching pole if this was the case. I guess ultimately we'll never know. Maybe he started lifting well before he got to Mirabeau?