Deliberate mistake: Marian is wearing pantaloons, or knickers, in the rape scene. Knickers were not worn by women until Victorian times, and then they were split at the crotch.
Continuity mistake: In the scene where Will Scarlet goes back to Sherwood after being captured by Nottingham, Little John attacks him calling him a traitor. In one shot the cuts on Will's chest are going one direction in the next shot, they are going another.
Continuity mistake: This one takes place in the main battle scene in the forest. Robin holds a rope, swings around, knocks a man off his horse, and lands on the thatched roof. The next shot shows him shooting an arrow, but this time (and this time only) he's holding the bow left-handed, not right-handed.
Revealing mistake: The fallen tree from which Robin gives his inspirational speech about freedom has obviously had several branches removed with a chainsaw. It may be hard to see the marks of the blade on a copy of the video, but in the cinema they were pretty obvious.
Continuity mistake: In addition to the other mistake of Robin crashing through the window that's obviously made of paper - when he first comes through, he makes a hole in the middle, but some of the window is still intact around the outside of the window frame. When it cuts back to Robin a second later, however, there is no "glass" in the frame at all.
Continuity mistake: Either some of the scenes take place over several years, or the leaves of Sherwood switch instantly between autumn-brown and spring-green.
Audio problem: During the scene of the birthing woman, Azeem says, "If you won't hear my advice...", but his lips don't move.
Other mistake: When the outlaws trap and rob a carriage in the forest, they put hooks on the back of it to keep it in place. But when the driver spurs the horses on faster, they run off, pulling the driver off the carriage and away behind them. There's no logical reason for this to happen, as you see the horses attached to the carriage, there is no evidence, either audio or visual, of the harnesses breaking, and in any event there really isn't enough force exerted for the harnesses to break to begin with.
Audio problem: When Wolf attacks Will before the hangings, the guards pull him off and he says "Kill him." But his mouth doesn't move.
Continuity mistake: When Robin is giving his inspirational speech to the people who have just fled the village, at one point Wolf walks and stands behind Will twice in a row. Then there's a reverse shot from behind Will, where Wolf should be visible, but he's nowhere to be seen. Cut back to the front view, and he's just where he should be.
Continuity mistake: During the final fight between Robin and the Sheriff of Nottingham, the cut on Robin's chin disappears after the fight is over.
Continuity mistake: When Robin and Little John fight in the river Robin's hair changes from being dry to wet to dry again despite falling in the river several times.
Continuity mistake: When John is standing on the platform looking across at his trapped wife, there's a piece of the railing next to him that's sometimes on fire, sometimes not.
Continuity mistake: Right before Wolf climbs down from the tree, the only clouds in the sky are way off in the distance. Wolf climbs down, and the very next shot of the sky is full of clouds.
Audio problem: When Robin and his men have Friar Tuck pulling the wagon you can hear the men singing, but in the shot facing them, their lips are not moving.
Continuity mistake: During the confrontation with Guy of Guisborne, over the issue of Wolf's poaching, Guy's teeth during the short conversation ("Well, well - Robin, welcome home") are coloured to look brown. But shortly after when Robin has him prone at his sword's end, and Guy identifies himself ("Guy of Guisborne, the Sheriff's cousin") you can see his teeth have not been made up for that shot - they are white.
Continuity mistake: Wolf (the boy) has semi-long, shaggy hair that hangs over his ears and eyes. During the archery contest, however, when Robin has to distract him by flicking his ear with the end of an arrow, his hair has been carefully slicked back to expose his ear during the close-up. In the wide shots, his hair has been left shaggy and down.
Continuity mistake: When the sheriff's men come to take Marian, she defends herself with a rod from the fireplace that was roasting some meat. If the rod had been sitting in the fireplace even for a few minutes, it's probably too hot for her to hold.
Continuity mistake: After stealing the treasure along with Tuck Robin and Crew open the chest soaking wet. A deleted scene in England - 'throwing the carriage into the lake' - made that bit of the film make no sense.
Continuity mistake: When Robin and Azeem are about to be launched in the catapult, look at Azeem's sword. When he first gets in, the blade is facing down. It then cuts to Will, then back to Azeem, whose sword is now facing blade up. Then they are launched and Azeem lands with the sword blade down again.
Chosen answer: The masked men weren't part of a cult, they were the Sheriff's soldiers, the same ones that Robin meets when he first returns home. They are just in hoods and masks to appear intimidating while trying to kill the noblemen, like Locksley.
Bishop73