Jim (Peter Graves), uses the wrong color stole for administering Last Rites to the dying priest. The proper color would've been purple.
During the bicycle scene a sign "8 MPH" is seen. European countries use the metric system.
During the initial chase scene a US style stop sign was observed with English wording.
As Jim and Doug approach the rectory in a day-for-night shot, a VW Beetle drives past with neither headlights nor taillights on.
When the police apprehend Schilling at the airport, Colonel Eckert examines two of the bills Schilling received from the IMF in exchange for the weapon component and declares them as counterfeit. Since it is obvious the bills are not U.S. currency, it was not shown or explained how the IMF team was able to obtain $50,000 in counterfeit currency of that eastern bloc nation in such a relatively short time span.
When Eric Schilling notices a piece of the photograph that Max lit and tossed in the trash can, the photograph only burned around the edges leaving the message from Dana intact.....which is unlikely as the small photograph should have been entirely reduced to ashes.