Corrected entry: In many of the official trailers for this film (whether the teasers or the theatrical trailer itself) we are given glimpses of Lt. Col. Stryker's Class-A uniform. On the left shoulder, above the unit patch, he wears both a Ranger tab and an Airborne tab. This is incorrect and against uniform regulations (both now and decades ago, when the tabs were created along with those respective units). A soldier wears either the Ranger OR Airborne tab, but never both at once. If the Airborne tab is worn, it is understood that the soldier has passed Ranger school and thusly earned a Ranger tab to begin with. If only the Ranger tab is worn, this means that while the soldier passed Ranger school, he is not Airborne qualified (yet).
Corrected entry: In the final scenes, Wolverine takes off the jacket the old couple gave him. He later escapes the island in his undershirt. However, the jacket reappears in X-Men 1.
Correction: We see him get up and start to leave, but we never actually see him get off the island; he likely picked it up before he left.
Corrected entry: The way that Logan escapes from the adamantium chamber is different from as shown in X-Men 2. In that film Logan was covered in blood and walks out through a long aisle, then breaks the door and runs.
Correction: What we see in X2 are fragments of Logan's memories. What we see in this film is the actual event.
Corrected entry: There only exists two "Welcome To Fabulous Las Vegas" signs in Las Vegas and the one Logan passes in the desert on his bike heading into the city does not exist there.
Correction: This means that the sign was a prop constructed for the movie, which falls under artistic license and is therefore not a mistake.
Correction: This is not correct; the tabs are worn concurrently all the time, and a soldier can be Airborne-qualified without being Ranger-qualified and vice-versa.