Searching trough dataset for broken pattern

I have a large dataset for asset tracking with RFID, that contains itemID, site, direction in/out and registration time (datetime). All assets should appear as a continous flow of in and out. When there is a missed reading, the dataset will show multiple in's or out's. How can I find (and correct) these missing data? I am using both MS Excel and MS Access on these data, and I can even process them throug SAS EG or equivalent.

Here is an example: I want to identify the fail in row 3 (reading IN twice, missing an OUT reading in Manchester)

Asset Direction Site Datetime Asset 1 OUT London 01-08-2015 22:00 Asset 1 IN Manchester 02-08-2015 05:00 Asset 1 IN London 03-08-2015 17:00