Music tempo changes is nothing new, Queen also did it with Bohemian Rhapsody, it is slow then gets faster. So that argument is invalid.
As far as the same riff, well sometimes two people's songs have similar parts to each other. Maybe one did copy from the other, but it is likely that it was completely unintentional.
I can see how the songs can be similar, but not the same song.
Now, Vanilla Ice blatanly stealing the riff from Queen's Under Pressure
and claiming that because he changed 1 note that it was original, THAT pissed me off.