Teenage Mutant Hero Turtles II (E) glitching

I was trying out the PAL version of "Teenage Mutant Hero Turtles II - The Arcade Game" on PowerPak, and noticed that occasionally the screen glitches for a frame or so. It looked like wrong tiles were mapped for the floor tiles. Same thing happened in Nintendulator (in PAL mode, of course). I wasn't able to make it happen in the NTSC release.

I verified that the ROM dump is OK according to bootgod's database.

Reproduce: Just play the first level for a few minutes. It happens kind of randomly, so may take a few tries.

Is this a known bug?

I wouldn't be surprised is this was just the result of sloppy NTSC to PAL conversion, like Mega Man 3 and those unbelievable scroll split bugs.