A khajiit will not use I am or I'm. So "No thief, this one " does make sense but perhaps they could have used "This one is no thief"
I'm pretty sure the OP is talking about the delivery of the line, not what the line is
Yes, exactly. The line as written makes perfect sense. Whoever was directing the actor should have gotten a better delivery other than, “I don’t know what this means.” Because we players know what it means.
I agree, I noticed that straight off. The emphasis is all wrong, they put a pause in as though it were a full stop, so instead of 'No thief, this one!' you get 'No thief. This one!' lol. It's Ezabi though, so I forgive her and just give her precious little ears a scritch.