Snuff the pre death which is the beating the Roman whip or cat tail had sharp barbs and beads on the tips.
This results in massive soft tissue swelling, vaso dilatation and internal trauma. The skin is ripped off the flesh hence why carrying the rough hewn cross beam with its splinters would be so painful.
Jesus had a double dose of the beating in a vain attempt by Pilot to show the Jews he had suffered enough.
No one had ever survived a full Roman crucifiction and there are accounts of many victims dying during the beating process and accounts of skin rupturing and bowel and organs coming out of the body during the whipping and beating process.
When one is nailed on a cross it is through the lower forearm in the space between your radius and ulna this is the only place that can support your body weight. Through your hands the nail will rip right through the bones and flesh. Being nailed through the interoseous space of the wrist it would most likely result in severing the median nerve leaving your hands useless. A nail driven through your feet would have been excruciatingly painful.
When you are hung by your arms you need your legs to help support you and assist breathing by pushing up, this helps the actions of the diaphragm. Remembering the distress state of the victim and the organ damage as well as the bleeding that resulted from the pre beating and whipping process. The crucifiction was designed to be lethal, humiliating and as an agonizing process that is possible. Each time the victim had to straighten his legs to help his breathing, the nail in the feet would have increased the pain causing shock and possible cardiac arrest to its victims.
The Roman solders broke the victims legs to increase the pain and internal bleeding but also preventing the victim from using his legs to assist breathing. It was a process of quickening the death via asphyxiation.
The fluid you correctly pointed out would have been a pericardial and or pleural effusion. The pericardial sac being peirced and full of fluid would have provided enough pressure to cause a gush of fluid and congealed blood. No need for the heart to beat as its contained in the sac surrounding the heart and lung. If you have congealed blood and pericardial fluid come out you havent been sucking wind for a while...you are dead.
