The article says he took shrooms. Many hallucinogens affect blood pressure and heart rate. (That would explain the bleeding from parts of the body with thin skin - like the eyes)
I was thinking that the only other time that bone marrow gets attacked and platelets don't form right is with radiation so I'd look that way.
It takes a lot of left turns for your body to get to that point. Unfortunately the first thing I found comes from CBS News, which is not trustworthy.
https://www.cbsnews.com/pictures/radiation-sickness-8-terrifying-symptoms/3/ Radiation sickness can cause bleeding from the nose, mouth, gums, and rectum. It can cause people to bruise easily and to bleed internally as well - and even to vomit blood.
The problems occur because radiation depletes the body of platelets, the cellular fragments in the blood that are form clots to control bleeding.
So there are the proteins that the liver produce that help with clotting but then there are the platelets themselves formed in the bone marrow, a lack of proteins from the liver is probably more likely than the platelets themselves not forming normally.