Here's a start. I made two examples. The one on the left uses the rules you stated literally. In such cases, if someone enters a rectification date that is earlier than the date the snag was logged, the row is not highlighted at all.

The one on the right highlights such rows as complete but also highlights that there is a logical error in the dates.

Let me know if this helps or if you need help understanding the conditional formatting equations.

Attached Files

RoomCheck.xlsx (10.7 KB, 18 views)