Not sure if this is a bug or not. It just seems strange that the person would yell about a failed steal while in combat, considering other 'directed' skills like pincer don't cause a yell while already in combat. I can't really answer any other questions about this fight directly as this wasn't logged by me.

<524hp/524hp 323m 456mv/530mv 13956tnl><4 PM civilized>
You parry Thief's stab.
You dodge Thief's stab.
Thief deflects your cleave with his shield.
Your slice MASSACRES Thief!
Thief parries your cleave.
Thief is convulsing on the ground.

<524hp/524hp 323m 456mv/530mv 13956tnl><4 PM civilized>
Thief tried to steal from you.
You yell 'Thief is a lousy thief!'
Thief is convulsing on the ground.