Here's how I see it playing out in the end.
Auryn will end up walking away because there's not enough profit in mining the properties.
They will have covered their cost of exploration by selling the 150 million shares they received at no/low cost.
They were under no obligation to disclose even their ownership of the 150 million shares - that was MDMN's obligation, let alone how they received them. If they wanted the price to go up, they would have said they purchased them on the open market (assuming they had). If they wanted it to go down, they wouldn't have even disclosed it. I believe they wanted to be 100% not blamed for "hiding" a material event, but didn't want to see the stock tank (though, once it became obvious what had happened, there really wasn't much they could do to stop that).
It's a "no lose" gamble for them. They find worthwhile mineralization, they can buy at less than 10 cents a share 85% of the company. They don't their costs are covered and then some.
Hard to find any fault with Auryn or Letts. Easy to find fault with MDMN's insiders, but then again, it has been all along.