The presence or absence pf a mid=po=int mat is not determinative of the presence of an uber-leg. TAR 6 didn't have one, TAR 9 didn't have one, TAR 10 had a mid-point mat that wasn't an uber-leg. So that factor, and Phil's presence, isn't determinative.
Until recent seasons, it was possible to use the cash distribution point at the beginning of a leg to help identify uber-legs. However, IIRC, there have been a couple of instances where teams did receive additional money at those mid-points.
The more determinative factor seems to be the presence of multiple detours and roadblocks. Yes, we had the one leg with two roadblocks and no detours in Beijing, but if we focus on the total number of such tasks, then it becomes less of a hiccup. But then, we've had both roadblocks and detours edited in such a way that they were presented on-air as if they were general "active" route marker tasks, so we can't always count on those.
But in general, the uber-leg has usually involved two detours and two roadblocks, with a midpoint where either Phil or the clue, without Phil being present, instructs the teams to continue racing. Whether the Manly midpoint introduces something different we'll have to see tonight. Also, if Phil uses "the mat" and not "pit stop" that may be a clue that the uber-leg mid-point is being used to determine who gets the Express Pass and the automatic U-Turn. We do have to stop thinking in terms of "the mat" meaning "arriving at the Pit Stop." We've known since TAR 7 that the two no longer always mean the same thing,