Replying to myself
I rescanned the file and it came up clean. It seems like the site detected that it had already scanned the same file some time ago with much older versions and showed me those results originally. That, negative scans with my installed monitoring software, and the fact that none of the files listed in the manual removal instructions I found are on my pc make me feel pretty confident I wasn't infected.
Still, I wish I had ran the scan before using the software so I wouldn't have any lingering doubt, but I suppose that's a lesson for next time.