Continuity mistake: When Robin and Azeem are approaching Dover Beach, there is shot behind the boat showing only one sailor standing at the stern. In the very next shot, not only is the sailor standing but suddenly so is Robin, at the bow.
Continuity mistake: When Robin is challenged by John Little after attempting to cross the river watch Johns staff. The scene cuts between shots from in front of and behind John. All shots from in front of him show him leaning closely on the staff, all shots from behind show him holding it to side and not leaning on it.
Continuity mistake: When Robin is talking to the Bishop about his Father, they are in a small chamber in the Church. Later on in the film, when the castle is being stormed, Friar Tuck enters this room and throws the Bishop out of the window. Only this time the exact same room is in the castle, not the Church.
Continuity mistake: Guy of Gisbourne's men come upon two of Robin Hood's men in the forest, trying to pull a log onto the path. The men see their enemies and run away, leaving the log sticking out onto the path. But the log suddenly disappears when Gisbourne's men go after them, and never again reappears.
Continuity mistake: When Will tells the sheriff he'll have to "respectfully decline" his execution, from one angle his hands are behind him holding onto the gallows, but from another angle they're outstretched.
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.
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.
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.
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.
Continuity mistake: When Robin, Azeem, and Duncan visit Marian's house for the first time, it's dreary and overcast out. But when Robin steps inside, there's suddenly bright sunlight coming through the windows. It then periodically cuts back to outside, where it's still overcast.
Answer: The white robes, reference to "the old ways", and pentagram across the map when the Sheriff meets the Barons suggests per-Christian Druidism; the upside down crucifix certainly implies Devil-worship. These two spiritual paths are, by nature, mutually exclusive. In short, a fictional pseudo-witchcraft invented for the film, yes.