In my campaign my cavalry usually take quite a few casualties when chasing down fleeing men, which I beleive to be realistic, in the heat of a chase the gentleman rider (used to teh thrill of the hunt) would often loose his head and break formation. Cavalry, no matter whom or where they are fighting, loose all effectiveness and fighting capability once out of a tight formation.

It would seem plausible that a group of fleeing infantry might look back to find that their persuers have spread out, that only two are chasing after them now, turn around with bayonets fixed, perhaps muskets still loaded and easily overcome the cumbersome horsemen.

In terms of the ability to fight, I would always put my money on infantry, what those men had to endure would, if it did not break them, turn them into supreme soldiers. Nothing could compare to the skill or bravery needed to survive the cold steel of a bayonet charge or the hail of a mucket volley.

Cavalry are in almost all aspects inferior fighters.