As and Avast User (not employee), I can't give you an authoritative answer. I believe they are talking about individual files either in the virus chest or when being scanned, but I can't see it doing anything else in the same folder unless they too are suspected of containing malware.
If as you say, that you had excluded a file/folder in the File System Shield settings then they shouldn't be being scanned to consider they are suspected of containing malware ?
