I'd redo, but I'm one of those fastidious mechanics you mention. Also, it only takes me 5 minutes or so to repack a BB, being an ex pro wrench during the loose bearing era. As an apprentice I was taught to listen to a repacked bearing for grit, and I had to do it again if there was any thing in there at all. The main trick is to lay out your bearings on a very clean rag. Don't use an old dirty one. Be very careful to keep your grease clean. Difficult if you are using grease from a tub. I personally don't change the ball bearings unless they are damaged.

Realistically, one tiny piece of grit is better than a dirty black BB bearing that hasn't been repacked, but it's really only your loss, as the BB won't last as long until it pits. If you don't ride that many miles it probably is not the end of the world. I couldn't let it be myself. Too OCD I suppose, plus long force of habit as an ex shop repair manager, etc.