I've seen similar behavior on my account, but it was especially prevalent after a recent update I released. Shortly after the update released, I had about 15 additional downloads and registered only 1 or 2 additional views in that period. I do have multiple downloads available, but they're just builds for different operating systems, so it's unlikely people are downloading multiple versions.
Is it possible that there's a download link people can use to download updates (e.g. special email link) that could register a download without a view? Alternatively, could automatically downloading an update through the itch.io desktop client do the same thing?