Bill,
Dupont did not surrender without fighting, it was only when his troops were too exhausted to continue that he asked for a truce.
Legendre, after the famous public harangue, was actually re-employed, eventually an attempt was made to include him in the 1812 hearing but since he was not present (being still with the army) the judges all refused to comment on his case.
Napoleon seems to have felt that capitulation 'en rase campagne' (not sure of the exact translation - in open field?) as distinct from the capitulation of a fortified place was unacceptable. Dupont however was in mountainous territory with all the passes blocked and had no chance of cutting his way out, according to Titeux at least.
I gather that N did make capitulation 'en rase campagne' an offence carrying the death penalty after this but even his lawyers wouldn't let him use it retrospectively. I don't think it was ever tested due to changing circumstance.

regards,

Susan