Not necessarily. I've served as a campaign treasurer before and IIRC, a receipt to the donor for contributions under a certain threshold wasn't required. The donation, even if not receipted, has to be included in campaign contributions.
Besides who's to say that an aide didn't get the information later off-camera? Candidates seldom do that if an aide is available to do it.
“Campaign finance disclosure law requires that all commit-tees and all candidates, regardless of their reporting sta-tus, as well as certain individuals and entities, maintain ac-curate and up-to-date accounts and records regarding their campaign-related financial activity.”