A good practice is to deliver a slightly incomplete, lo-res (MP3), or watermarked file, prior to final delivery of hi-res files. That way you can get confirmation from the client that everything is in order creatively, and from a production standpoint. If you have the client's approval, prior to your final delivery, then there should be little reason to contest your final delivered work.

If you ever run into anything fishy, don't hesitate to contact us here at help@airgigs.com.