When Robin is seized by the guards at the Tournament, the manner in which he is tied up changes. In the initial shot, his arms are at his side, but in subsequent shots his arms are tied behind his back.
During the puppet show, they say Prince John is "too late to be known as John the First" if he becomes king. In history, John did become King John I in 1199, and as of 2012 is the only English king to be named John.
At the Archery tournament, Little John has been wearing his Duke of Chutney clothes to fool Prince John. When Robin Hood, Maid Marian and Little John are running away after the fight, Little John suddenly has his outlaw clothes on. But when he reappears to grab Lady Kluck into the forest, he's back in his duke clothes again.
When The Honorable Sheriff of Nottingham walks up the street towards the well, the star on his costume is to the left, and the feather on his cap points the same way. In the next shot, the Sheriff walks past the well and his character is inverted; to save animation time.
When Robin Hood and Little John (both disguised as gypsies) are allowed to kiss Prince John's hands, Robin is seen sly-fully slipping off one of the Prince's rings before kissing one of his hand, while Little John kisses off the stones from the Prince's rings on his other hand. In the next scene however, you see Prince John still has rings (sans stones) on both his hands.
Robin Hood, disguised as Nutsy, tries to unlock the prison gate while singing a lullaby to the Sheriff in order to keep him half asleep. Then the Sheriff praises Robin while scratching his own belly with five-fingered hands, while during the rest of the movie his hands have just four fingers.
During all the commotion after the archery tournament, a duel erupts between Robin and the Alligator announcer, who is wielding a sword and shield. Shortly after the fight, the alligator can be seen in a completely different area about to announce to the audience. He then gets run over by the moving tent that passed him half a minute ago. He also doesn't have a sword and a shield.
When Little John realizes the wheel of the Royal Coach has solid-gold hubcaps, he is shown removing only two of them (just before moving to the big chest to empty it of its golden contents), yet in the next scene, all four of the hubcaps are shown to have been removed.
The rings on Prince John's fingers change from hand to hand and sometimes disappear completely. This is most noticeable during the tournament scenes where Prince John is talking to 'The Duke of Chutney' and also during the scenes where he is asleep and Robin is stealing the money bags from his room.
During the fight that ensues after the archery tournament, Robin Hood shoves Prince John's throne off the platform onto the Sheriff's posse. Later, Little John in the "runaway tent" comes crashing through and hits the throne, which is now back in its original, upright position.
When Robin and Little John are on the side of the road posing as gypsies to attract Prince John and his patrol: in one shot, when they are bowing, Robin is barefoot; in the next shot, his shoes are back on.
When Little John is fighting the guards into the runaway tent, the tent only has one entrance. Then when Lady Cluck is chased into the tent, the tent has an entrance in the back. And then Little John runs back into the tent and Lady Cluck gets thrown out the back of the tent and the back entrance is gone.
During the "runaway tent" part of the archery tournament, the Sheriff ends up being forced into Prince John's throne as it's being carried by the tent. However, when we see Little John escaping from the tent, and just before the tent crashes into the tower, the Sheriff and throne are absent.
Near the end of "Love," as Robin and Marian finish their romantic moment and are just about to join the rest of the Sherwood Forest gang for "The Phony King of England," there is a touching moment where they walk through a cave beneath a flowing waterfall. On the other side, they emerge... on flat ground, with absolutely no river in sight.
Historical inaccuracies inherent to most versions of the Robin Hood legend. In the movie, Prince John is shown raising taxes on the poor people. In reality, Prince/King John Lackland was notorious for raising taxes on the nobility. Similarly, King Richard is depicted as a loving king who guards England dearly, when in reality he spent all of his short leisure time at his French estate, and once said he'd sell London to the highest bidder if he could.