In the shooting scene after Coogan and Vanessa left in the Porsche, the P08 Luger, with which Jeff kills his three pursuers, is seen at one moment in a take from behind with the breech opened (magazine empty) and in the very next moment in a take from the front with the breech closed (pistol loaded). This continuity-error is about ten minutes into the movie, in a scene where Jeff lies in the sand and shoots the last attacker on the other side of the burning car.
After Jeff fires numerous holes into the glass elevator, we see Vanessa looking out the glass which has no holes in it.
During an extended car chase that takes place on the island of St. Thomas in the U.S. Virgin Islands, the cuts from one minute to the next make absolutely no sense, as they jump back and forth from various locations all over the island with no regard to direction or time of travel.
In the opening chase sequence, the white Ford Mustang changes from a 1968 model year to a 1967 model year.
In the last scene, Jeff is shooting sniper shots, across building tops, from quite a distance at a moving target and through a glass elevator. The rifle, shown, being used is a Ruger 10-22; a .22 caliber semi-auto rifle. At the distance and target, the .22 caliber weapon would be completely ineffective.
Tarantulas are not found anywhere in Europe. While it is possible that the tarantula is an escaped pet of some sort, it is highly unlikely.
There is no toilet in the jail cell.
Cars with screeching tires on dirt roads.
Telly Savalas' character repeatedly makes reference to Charles Bronson being a generation under him. In reality, the two have only a three-month age difference with Bronson actually being older.