Matrix knocking out Enriquez on the plane.

One wonders how Enriquez got a hammer and nails through airport security, but I guess we are talking about over a decade before 9-11 so things were a lot more lax at LAX. The bigger question would be how Enriquez would have expected Matrix to successfully accomplish his mission of killing El Presidente if he showed up at the palace with several nails protruding from bleeding holes all over his face. This would likely have attracted a lot of unwanted attention from Val Verde police and compromised Matrix's ability to get anywhere near any place of importance within the 24 hours period.

I also couldn't imagine the stewardesses and fellow passenger standing by idly while Enriquez attempted to perform an impromptu invasive procedure on a 6'2" Austrian bodybuilder.