Well, there is that, but the general consensus is that he was just trying to piss off Tenzou.
It worked, naturally.
As an addendum, @NanoPulp suggested:
I think he threw on the ground in a mock attempt to test its authenticity, which would show as doubt in Tenzou’s trustworthiness
Or rather, as like an insult to Tenzou’s honor? Honor? Is that the right word? But yeah, that kobold is playing high level games