With an honest person, if they commit a crime but claim it was an accident, you can take that into consideration. Actions speak louder than words, but you can still take intent into consideration if there is no reason to doubt their claims of intent.

But with a dishonest person, repeatedly lying to you, they lose the protection of intent. It doesn't matter if they call something an accident, we as a society must protect ourselves by presuming it was intentional and they are lying about their intent.