I honestly don't know what your concern is. Are you considering giving Dave access to anything that any thing that isn't available to any of your company's other customers? Even if Dave did discover something and did disclose it, I don't think that you'd be any more liable than your company's shipping department would be if one of your company's other customers were to disclose something. Have you even signed a formal NDA with your company? I don't care what your company's POLICY is, have you signed an NDA? If so, exactly what does it say?
So far, all you're talked about is the conformal coating. Is this a commercial product or something that your company developed and ONLY they use?
I think that you're over thinking this, unless you intend to send Dave your company's complete Technical Data Package for this product. Sending Dave a sample of one of your company's products shouldn't be any different than if you or anyone in your company sent a sample to a potential customer or your or your company sold one.