Well avast is catering for the user base as a whole not necessarily for experienced users, who are to the most extent able to take care of themselves and set their Actions accordingly. However, most avast users would be unable to make the decision or test to ensure that they are certain it is 100% clear.

There is a simple means of adding a file to the exclusions from the virus chest. Open the chest, right click on the file name and select ‘Restore and add to exclusions.’