Welding Tips and Tricks

I had someone say a couple years ago that you can mig weld over stick weld but you shouldn't stick weld over migweld.. any truth to this.

I don't see any reason why you can't weld one process over another.
tig root and hot pass, 7018 fill and cap.
Unless there is porosity or lack of fusion, you can stick over mig any day of the week.
Where did you hear this?

~John