I have given propofol many times, and when I saw that the saline bag was cut open with the bottle inside, I was puzzled. Still am. Generally, you have an IV line with saline and the propofol is hung via it's own tubing, sometimes to a dedicated IV site, and sometimes the propofol tubing is plugged into the saline tubing at the closest port to the patient. The IV bag is NEVER opened in any situation during an infusion. That would contaminate the line and possibly introduce bacteria into the line. IMO, the bag may have been cut and the propofol bottle thrown in just as you are getting rid of it to be thrown away. In this, or any case, though, that would be a pointless, time consuming step. I still don't understand what that's about. At any rate, the propofol I used for infusions were sent up from the pharmacy with a little bag that would hold the bottle and be used for a hanger. Looks like they make them with a plastic hanger on the bottle nowadays.
Drugs are metabolized by the liver and kidneys in both men and women. Diprivan, however, is a lipid based drug, which may make it metabolize differently depending upon the amount of fat on a person. In MJ's case, he was so thin, I can't imagine how this would have behaved in his body. Seems to me the health of the liver would be more important. Also, if he was accustomed to getting Lorazepam, he would have some tolerance, but the only time I've heard of a patient getting that much of it is when I took care of burn patients in an ICU setting and the real bad ones would be on a drip. Of course, THEY WERE MONITORED, unlike MJ.