Doc keeps referring to "ephedra" (pronounced uh-fed-ra in actuality, mispronounced ef-idi-rah throughout the film) as being a naturally occurring substance in the body. In fact Ephedra is a genus of plant. A particular type of Ephedra plant naturally produces the chemical ephedrine, a natural stimulant and the basis of pseudoephedrine more commonly known as Sudafed. Ephedrine does not occur naturally in the human body, and Ephedra isn't even a chemical. The actual "adrenaline" produced by the adrenal glands in the body is primarily epinephrine. [It is EPINEPHRINE they are talking about and that he is supposed to take, not Ephedra.]

At the end of the film when Chevy is falling from the helicopter, he breaks the bad guy's neck and he starts falling a lot faster than Chevy. One of Newton's laws states that two items will fall at the same speed. Chevy coudn't have pushed him to fall faster due to him not havving anything to push against, therefore the guy shouldn't have started falling faster. [Actually, both bodies had downward inertia. If Chevy forcefully pushed the dead man up, Chevy would slightly increase his downward momentum while momentarily decreasing the dead man's because he was pushing with his own inertia and against the dead man's. The actual increase in Chevy's own speed is small, but, when coupled with the slight, temporary decrease of the other man's, the difference appears much greater.]

As the two characters fight near the end, the helicopter is hovering right around rooftop level of the large skyscrapers downtown (clearly seen out the door). This would place the helicopter right around 1000 feet. As they fight, the helicopter ascends for perhaps 10 or 20 seconds. When the characters fall, it takes our hero 91 seconds from helicopter to splat. After about 15 seconds, he would be at terminal velocity: about 120 mph. Let's subtract that 15 seconds and just calculate he fell for 76 seconds at 120 mph (176 feet per second). That means he covers 13,376 feet. So, with the first 15 seconds, at least 15,000 feet. Now, the service ceiling for the Eurostar AS350 helicopter they were on is about 20,000 feet, so it could have been high enough, but its rate of climb is only about 2,000 feet per minute, so to reach the altitude from which our heroes fell, it would have needed about 6.5 minutes of climbing, not 20 seconds. There is no way the helicopter could reach the specified altitude in the specified time. [All well and good except that the climb to altitude was most likely time compression, used frequently in films. Filmmakers rarely use real time to heighten suspense.]

That last message Chev left on Eve's answerphone should have been very distorted with Chev's voice barely distinguishable over the sound of the wind (he was falling thousands of feet!). But Eve gets a nice clear farewell message to remember him by. [It all depends on the type and quality of phone. My cell sounds horrible, even with only a little wind. My co-worker's cell always sounds clear, even when driving with the windows open at 110 kmh.]

Chev gets shot in the leg in the warehouse scene. However, he descends the lift and when he reaches the bottom he is walking just fine, with no hint of a limp or anything to indicate him being shot. The leg shot is never mentioned again. [It was a flesh wound, painful, but not debilitating. Besides with all the drugs, adrenalin, and other chemicals in his body, he probably wouldn't have felt it for long.]

When Chevy jumps in the swimming pool near the beginning, he is in there for quite some time yet his phone still works perfectly when he gets into the cab. [My two-year-old son flushed my wife's cellphone and it still works.]

The only way to keep straight falling is to have your arms and legs spread out. However Chev is able to move his left arm freely to make a last phone call to his girl. He should have been spinning wildly and out of control. [This is just not correct. The only way to *steady* yourself *while* "spinning wildly and out of control" is to spread out your arms and legs, but you do not need to *keep* them spread to maintain balance. Many skydivers "dive-bomb" the ground with their arms and legs held firmly together without any rotation whatsoever.]