We Were Broadsides By A Deer While We Were Doing

We were broadsides by a deer while we were doing 70 on the highway. My passenger rapidly experienced pain and swelling to her lower leg where the deer's head struck her. ER visit results were no fracture, just swelling with hematoma. That evening clear "water blisters" developed where we think the antler, which broke off, struck her leg because of a small red abrasion there right after the impact. I have been in EMS since 1989 and have never heard of such blisters associated with contusions or hemotomas without associated thermal burn. Any ideas? I have pictures but don't know if I can transfer them to computer.