Oh come on, it's not a scam and he's not stealing anything. It's clearly mentioned on the license and it's up to the users to go through it (like any other open-source plugin or software they use). At the end of the day the plugin creator was polite, understanding and returned money back even though he was not obliged to do so. It's a win-win situation as they clearly describe it, but the OP wasn't satisfied with the high (30%) percentage.
How is hiding 2% in your wiki (instead of in LICENSE where it belongs), and then taking 30% instead of 2%, not a scam? If someone listed a price of $2 for a burrito and then charged you $30 at the register, you would not consider that OK.
