Perhaps the main problem with this report is that it looks at all data classes, some of which probably shouldn't be included (Eg. Inv_Audit). I think some investigation into what inventory classes have been updated the most recently for that computer will help explain it for you.
Try this query (will find dataclasses updated within the last 'N' days for specified computer name):
DECLARE @NDays int
, @ComputerName nvarchar(255)
SET @NDays = 14 --set number of days here
SET @ComputerName = 'Pepe' --specify computer name here, can use '%' wildcard
SELECT c.[Guid]
, c.[Name] [Computer Name]
, dc.[Name] [Inventory Class]
, rus.ModifiedDate
, rus.[RowCount]
FROM vComputer c
INNER JOIN vResourceUpdateSummary rus
ON rus.ResourceGuid = c.[Guid]
INNER JOIN DataClass dc
ON dc.[Guid] = rus.InventoryClassGuid
WHERE DATEDIFF(dd,rus.[ModifiedDate],GETDATE()) <= @NDays
AND c.[Name] LIKE @ComputerName
ORDER BY c.[Name], ModifiedDate DESC
From the results, I'm sure you will see some data classes changed recently that you didn't expect.
IMO, the report should only be looking at the 'AeX AC...' inventory classes. Given that those are all the basic inventory data classes and if there hasn't been any data for them in the specified timeframe then the computer should be considered as inactive.
I've gone ahead and modified a clone of this report so that it only looks at the 'AeX AC...' inventory classes. You can import it and see if it provides better results. There still may be some of the 'AeX AC...' data classes that have changed recently, especially if you have done any network discoveries targeting that machine while on, or AD Imports while it was still in Active Directory recently.
The new report is attached to this thread. Let me know if you have further questions.
-Tyler