It is not sufficiently emphasized in our country that bruising can also appear post-mortem. We report two cases in which we observed discolorations which looked like ante-mortem bruising
This type of bruising is different than what would have occurred in Martin's hands.
Case 1: A 37-year-old man was found prone on a river shore and taken out of the water by a rescuer by grasping at the right upper arm approximately one hour and 30 minutes after death. At inspection, two thumb-sized discolorations resembling ante-mortem bruising were observed on the lateral and frontal surfaces of the right upper arm. Case 2: A 40-year-old woman was found prone immersed in a moat and taken out of the water in the above-mentioned manner approximately one hour and 45 minutes after death. At inspection, two thumb-sized discolorations appearing to be ante-mortem bruising were observed on the inner surface of the right upper arm. The cause of death in both instances was drowning. Bibliographic investigation revealed that bruising of significant size can appear after death
If someone had pressed on Martin's hands with the same pressure needed to lift those bodies, it may have left a bruise, but I think the point the Forensic expert was making is that no blood movement...no swelling in the hands after death due to hitting someone, the way it would happen for a living person.
Additionally, we believe that post-mortem bruising should be sufficiently considered, because it can be important whether a person was grasped when he or she was alive or dead.
You would have to watch the actual testimony to see exactly what he said about the hands...