Is this part of the glitch?

I was playing Pokemon Red and I did the Mew Glitch. After I caught Mew, I flew to Cinnabar Island and went over to the east coast (next to the gym) and I used surf. Right when I hit the water, I went into battle. I thought that I encountered 'M Block, but I actually went into battle with an Ivysaur at lvl. 7! I think that part is also glitched!?!?