During "What a Day In London", a character appears who is intended to be William Shakespeare. In reality, Shakespeare died on April 23, 1616; preceding Pocahontas's arrival in London by less than two months on June 12, 1616.
When Mrs. Jenkins is introduced to Pocahontas, she offers to "put on some tea". Tea is not known to have been drunk in England at the time the movie is set (it was introduced about 40 years later). Certainly it would not have been readily to hand in a typical English household.
As Rolfe's ship sails into London, Pocahontas is at the bow, looking ahead, with her hair blown backwards. The ship is running before the wind, so her hair should be blown forwards, just as the sails are.
When Pocahontas first arrives at John's house, John leaves to see King James and her dress strap is on her right shoulder. When he leaves and closes the door, her strap has suddenly moved to her other shoulder. In the next shot of her, the strap is back on her right shoulder.
In the final battle on the ships, Ratcliffe appears behind Pocahontas through a flag. She's wearing her necklace. In the shot right before John Smith pulls Ratcliffe's cloak, her necklace has disappeared. When we see her again, it's back.