I was getting:

Exit code returned non-successful value: 2
Package: Irfanview.
Command:
cmd /c rmdir /s /q "%programfiles(x86)%\irfanview"
Removal of Irfanview successful.

i.e. the rmdir was returning 2 ("directory not found") but because that
was the final remove cmd and the package check condition was no longer
satisfied, wpkg was happy that the removal had completed.