OP, thank your fairy godmother that you mostly walked away from this. Someone rear ending you @ 45mph+ when you are at a standstill could have easily killed or crippled you. Be glad you were in a 6mt...with your foot on the clutch/neutral and not on the break (as you would at a standstill with a DCT?). Think how much worse the impact would have been.
I had a woman merge into freeway traffic in front of my Nissan Titan while I was traveling @ 65mph...the woman did this @ 10mph (and that's being generous). I ended up side swiping someone trying to share a lane with them in order to avoid creaming her @ 50mph+. CHP actually ticketed the woman who merged @ that speed and bluntly told her she is lucky that I reacted the way I did.
...hopefully the accord has sufficient insurance, or you are going to discover how good your carrier is.