TIL: Item sold by the company through Amazon is NOT considered verified purchase

Today I learned that items purchased THROUGH Amazon, but fulfilled directly by merchant, is NOT considered an Amazon Verified Purchase. 

But let me start from the beginning. 

I have a wallet collection. Yes, I know, it's weird. 

Recently, I found a coupon on something I wanted, a Dango D03 wallet. Normally $79, the coupon took $40 off. So I bought it. It was sold by Dango Products, supposedly the maker. Right? 

Purchase of a Dango D03 Bifold with DTEX through Amazon from Dango Products 

Okay, so I used it for a few days, and wanted to review it. Guess what happens: 

Amazon has noticed unusual reviewing activity on this product.
Due to this activity, we have limited this product to verified purchase reviews. 

And the reviews indeed look rather weird. The most recent reviews are either 1 star or 5 star, suggesting some sort of review bomb or counter-bomb in progress. 

So what does Amazon consider to be "verified purchase"? Apparently NOT merchant-fulfilled orders, but only FBA (fulfilled by Amazon) orders. As per Amazon:

An "Amazon Verified Purchase" review means we've verified that the person writing the review purchased the product at Amazon and didn't receive the product at a deep discount.

I paid through Amazon, but the product came directly from Dango. Yes, I check the envelope. That doesn't count as verified purchase.