Not to sound unsympathetic but it's your responsibility to leave enough room between yourself and the vehicle in front of you to react and stop in the event of an emergency. Now if the truck in front of you had hit the SUV that made an unsafe lane change in front of it then that truck driver might have a case. But you simply hit the person in front of you who had to stop quickly. So that one is sadly your fault
North Americans really don't know how to drive and I have seen very few that leave enough room between themselves and the vehicle in front. I remember being tailgated in my old Porsche by people in SUVs and trucks etc. if I had to brake hard due to some circumstance there was no way they were going to stop as quickly as I could. I would often then be forced to slow down significantly due to their dangerous driving or would sometimes brake check them to make a point (also not really safe but hopefully woke them up a bit).