Actually, he's right. Generally "sprite" means bitmapped images over a background. Perhaps you should have used "bitmap" or "raster".

The reason why 16-bit apps don't run well is because normally the CPU has to switch out of 32-bit flat mode to real mode (or even "unreal" mode) where there's no memory protection. This causes a whole lot more problems than the obvious overwriting of important data. That's also ignoring the complete non-existence of the DOS-interrupt vectors on an NT box.

BTW, I've never seen an "8-bit" app on an x86 architecture.