That was my first suggestion, but according to the Dev, the people who send him the data basically told him "we make no promises it'll be in the correct format, and you're on your own once we send it to you."

I've suggested long-term it would be better to catch "bad" data on the import side, but he's thinking the app is going away soon enough that it wouldn't be worth the effort to fix / improve / replace the BCP import with an SSIS package.