A combo implies that you do not drive with all wheels on the ground in between stunts
(like a bmx or skateboard)
The backflip to bus landing was pretty cool though.
Though I agree with this not being a combo, I can't say I agree with this definition being used for stunting.
For example: if there is a bump on a rooftop that can take you to an even higher rooftop which is unreachable unless you extend your runup by jumping/bumping from ground level, landing on the first rooftop, drive to gain some more speed, and finally bump the bump on the first rooftop to land the second rooftop... is this not a combo?
OT: that was really awesome, you should have stayed on the bus tho D: