Sodium pentothal, a.k.a. the "Truth Serum," is commonly used to extract information form prisoners in this kind of shows. However, while under the effect of the drug, the patient may lose his inhibitions, but he does not lose self-control, which means that Will would not have told anything he did not want to.
In the gun battle between SD-6 agents and CIA operatives in Indonesia, Dixon's backup agent's gun is clearly empty as the slide is locked open, yet he pulls the trigger and an audio gunshot is heard.
Sloane says they have been tracking Sark since he left the club in Paris, and that he is on a trans-Atlantic flight. However, when he lands, he is in Geneva, which is east of Paris, not across any oceans, and still in Europe. Additionally, it would not take as many hours to fly from Paris to Geneva as Sloane claims.