When Dee and BB are saving Kayo and her friend, Dee is shown with the friend in her arms and BB is promptly shown rescuing Kayo. However, when BB goes to get the Buster Gun, she's shown holding the friend instead of Kayo.
Near the end of part 5, the Triad/Demon Beast hideout is shown where tens of young men and women are shown as followers to the Demon Beast. However, once Muneto and Agent G7 invade, only three followers are shown retaliating.
When we see the campus that Kayo and Muneto went to after the invasion, it's completely in shambles from the last time; it's deteriorating, the windows are broken and there's even blood on some of the walls. However, the only damage done to the campus building originally were multiple holes in the roof-top.
An early visit to Kayo and Muneto's campus shows ghosts of the demon beasts assaulting the ghosts of college girls when none of that ever happened in the previously.
The flashback representing the previous end and how the Demon Beast was defeated is completely inaccurate. The original Demon Beast was also redrawn from the flashback.
When Miki is first assault by the Demon Beast, a split second shot of a close-up reveals the tentacle closest to her skirt was not completely drawn in.
With the Japanese dubbing on, when Yoshkio is murdered, her voice actress is still screaming even though the character's head was completely (and nonsensically) decimated seconds ago.