Pooled blood from the abdomen will flow for sometime. Blood that comes from a traumatized person has a high bilirubin content doesn’t clot well and also separates into red blood and serum and will also flow much better than normal blood. It also stays red when staining. That which flowed from the Lancia (spear) wound in the side shows that was exactly what it was, as it formed a corona of clear serous fluid around the core of red blood. When the body was moved, it drained from the pleural sac and abdomen.
Depending on where wounds exist, a body will continue to drain from a dead body until the blood clots with exposure to air.
Other blood flowed while the Man on the Shroud was still living, hanging from the cross, from the effects of a very severe beating and flogging with a Roman Flagrum.
I once made a Roman Flagrum for a lecture series on the Shroud I was presenting. It consists of a wooden handle with a leather wrapped handle and three leather thongs. At the end of each eighteen inch long thong were two 3/8 inch lead balls. I had no idea what a vicious weapon that Flagrum was. My homemade one was a bit simpler than this one, but close:
Just a moderate swing with that Flagrum would imbed those balls 1/2” deep into a four by eight piece of pine wood. I wasn’t even putting any effort into it. Think what that would do to human skin if it went that deep into hard wood. Think what a willful, hard swing would do. Just such a Flagrum is what Pontius Pilate ordered used on Jesus Christ with the intent to let him go. Think of the trauma this created in the body and bilirubin released.
The number of double-wounds from the scourging counted on the body, legs, and arms of the man on the Shroud is over 135 and appear to have been applied by two men of differing heights from two different directions.