Accuracy of mysqldbcompare vs other tools like pt-table-checksum
It is a non goal of pt-table-checksum to show you the actual differences.  However, there is a companion tool pt-table-synch  which can read the checksum table generated by pt-table-checksum.  It will take the bounds of chunks where master/slave checksums differ and then scan with in those to identify rows that don't match.

It will even generate replace statements ready to execute on the slave to get it in synch with the master.