That FP test doesn't say anything at all.
Where is the list with samples that they have used?
What settings did they use in all the av's?
Example:
They use 100 samples.
75 installers created with NullSoft, 25 Created with other install creators.
avast has a flaw in de vps if it comes to scanning installer created with NullSoft.
Sure, avast will fail at 75/100
But it does not mean that avast has a lot of FP's.
In fact it is just 1.