Man, I don't know what happened but from what I had read before he was a good kid who was trying to fix his life after making some mistakes. Sorry to hear about such a young man passing like this.
Pulmonary embolism? Not that uncommon after surgery, even after a procedure on a knee. Seen it a few times during 30 years of practice. Why do so many guys wait so long to seek medical care after experiencing chest pains?