Driving & Driving Test Tips: who hit whom, discerning, pound vehicle, x mass

Question

Eclipse Mr. Winter,  I will attach a picture of my dented Eclipse to this.  I had just backed out of my spot in a parking lot, and as I was about to turn my wheel the other way, with my foot on the brake, I saw this monster Hummer backing toward me.  I honked my horn.  I wanted to move, but there was no time--the Hummer kept backing towards me, and 'boom,'she hit my hatchback hood--the vertical part.  She may have hit it with the tire which hangs on the back of the Hummer--an 8600 pound vehicle.  My Eclipse, is almost a 3000 pound vehicle.  I have a 2 part question:  1# from looking at the dent in my hatch hood, is there anyway of ascertaining, other than from my account of what happened--of who hit whom?  I would think that even if we were moving at the same speed---#but I was stopped)--but if we were moving at the same speed---which when backing, I presume is about 10 mph tops--that if I hit her---the dent would not have been so big.  I think the Hummer lady told the insurance company that I hit her tire hanging on the back---but from the little I know about physics--it would seem to me that even if I had been moving, and we had been moving at about the same speed--and I hit her---then the dent would not have been as big?   The second part of this question is this---if momentum=mass x velocity---what causes more injury---the weight of the striking vehicle or the speed? Because my neck and head were very sore for quite awhile after this. THANK YOU

Answer
thought I had already answered this.

There is no way to figure out who was static and who was moving based upon the damage alone.

since mom=velocity x mass if either increases it is the same resultant increase to momentum

Pain has bee shown to start at 3 mph change in speed