That is the very long straight part of the track! He was probably just checking out the tires, or keeping them sticky, maybe even messing around with the EDC. Who knows maybe he seen you and decide to just have a little fun.
By the time you get to that part of the track those tires are so sticky by then anyway. Man I love that track!
I got sideways with DSC ON this past weekend by accident
(chasing down a Porsche GT2). Downshifted to late, did it into the turn instead of right before the turn. I would have to say that the M3 does hold its own. I pushed it hard into that turn. DSC light was going off before the tires ever kicked out. Of course that light stays pretty much blinking most of the way around that track anyway. I never dropped a beat. The car made a lot of noise, (from the tires) put on a nice quick show for all the people standing by and was on it's way! It all happen so quick!