Plot hole: When the DigiDestined return to the real world, Izzy states that only a few minutes have passed by despite the weeks that have elapsed in the DigiWorld. However, in an earlier episode, Tai returns to the real world for hours and upon his return to the DigiWorld, only a few weeks have passed by.
Plot hole: Series 2: In the episode where Yolei and Sora go to Russia, they can't talk to the Russian kids, because they can't speak Russian. However, the Russian digimons speak English and they surely speak Russian, so Yolei could just have asked them to translate what she was saying.
Answer: He was in pain from the black gear that was stuck inside of his body.