I've probably stopped at 50 or so accidents over the years and offered help. On only 3 occasions, anyone was even interested in knowing who I was. One was a cop who was so impressed that I even stopped, that he took my name and number to give me some follow up on the condition of the guy. The other was the Fire Capt, who later sent a letter of appreciation. Most times, everyone is so wrapped up in what's going on that nobody bothers to get any info (at least that's my experience). The only other time someone bothered to get my info was some dumb-ass cop who wrote me up for "unsafe parking" when I used my vehicle to block oncoming traffic from hitting a downed biker.
Erik