Continuity mistake: In one of the funnier scenes of the movie, a tipsy John Wayne attempts to escort Maureen O'Hara up a flight of stairs while drinking from a bottle of whiskey. They fall to the foot of the stairs, and the bottle is empty. After bopping Wayne on the head with the bottle, O'Hara throws it against the wall, and it's miraculously full again.
Continuity mistake: In Kate's hotel room, when she's trying to get away from GW she steps backwards through the hotel room's doorway onto the porch, and falls straight through the broken wood railing, but when GW looks down at Kate on the pile of hay, there's now a window behind GW, not a doorway, and clapboard siding has suddenly appeared on the hotel wall as well.Super Grover
Continuity mistake: When Kate's trying to hide from GW she heads to the restaurant which has double-hung style windows with muntin bars, and red curtains across the windows' lower portions, but in the interior shots the red curtains have vanished, and when Kate jumps out the window it's now just a single pane with muntin bars used for the stunt.Super Grover
Continuity mistake: When McLintock et. al. head to the clay slide, which is just outside of town, to check out the report of a kidnapped girl, it is very early in the morning. When they arrive, there is an argument, the girl shows up, and there is a brief fight, then they head home. But when they arrive home it is late at night.