Factual error: When Starfire gets out of the totalled car, there is a road sign visible. It is a settlement exit sign, denoting the exit of Königsstetten and Zeiselmauer as next settlement ahead. Obviously the makers tried to be extra thorough nailing down their "outside Vienna" location. They started OK - both Königsstetten and Zeiselmauer actually ARE outside Vienna - but then they completely botched it: Not only did they use a German black-on-yellow "StVO Zeichen 331" instead of the Austrian "StVO Hinweiszeichen 17b" which has black writing on a white base with a blue rim and doesn't list the next settlement, but they also put 852km as the distance to the next settlement, which is more than the length of Austria west to east. The real distance is 3.8km.
The Day Danger Walked In - S3-E5
Factual error: Higgins, Thomas, TC and Rick are locked in a freezer. Their barber friend is tapping his horn in "a pattern" Higgins says is Morse code, and announces that he tapped "move back." Not really. I know Morse Code. All I got (along with a few undecipherable things) was TOERT NMU ETM CEA OFJ DER WK. No way that spells "Move Back."
Making Dead Things Look Nice - S4-E7
Factual error: When Carolyn leaves the hotel and gets into the taxi, you can briefly spot the license plate. In Austria, the first part has only one or two letters; here it is three letters. For Salzburg, it should be S or SL.
Factual error: Sir John Franklin, Francis Crozier and James Fitzjames all wear a crown over an anchor on their epaulettes, the rank badge for a captain with over three years in rank. This is correct for Franklin and Crozier, but Fitzjames only held the rank of commander, and should therefore only be wearing an anchor on his epaulettes.