I was in lane against a kelvin today and noticed a bug, he was double throwing frost grenades. The ability has a 3 second cooldown between using charges, and doesn't start with charges anyways. they were coming out about 0.2 seconds apart. he was insta-clearing waves (and my forehead) at level one. seems like he was aware of the issue and abusing it. I was unable to reproduce the bug in sandbox, the player in question was 'Buzz', maybe he can shed more light on the issue.