I didn't notice - what did he sell it for?
Anyways, rageblade is twice as effective on melee as on range - it's no wonder that it's not OP on tristana. It's only still effective on Kog because he can double the AS cap (making it equally effective on him).
The item is still semi-broken. Not to the extent that it can't exist as is... Make it a 3300g item and it's no where near OP. At 2800 it's too much of a bargain, and it's power comes from being insanely cost effective. Regardless, it's not nearly as slot efficient as other items (at least on Tristana, there are champions who abuse it better and it IS effective on them) and it makes sense to sell it for something else. It's power comes from being an easy item to complete quickly and letting you hit power spikes earlier, therefore allowing you to gain further advantages, and using those gold gains to get further ahead.
The only nerf rageblade needs is to increase the cost to 3100-3400g. Add a dagger to the recipe if necessary.