Defender and Anti-Virus

Hi,

After good job done by MSAS, WinDefender is now doing the job. I have no
complaint but a question. With last version, I needed to "explicitly exclude
MSAS from anti vir guard in order to prevent a double check of any file.
With the new version, I didn't notice any activity in AV during scans.

Does anyone know if there is a special feature in Win Defender designed in
order to by-pass AV protection during scans ?
The alternative is my AV is fooled by anything else I must search for ;-(

Thanks for the answer

Jacques