From the Promissory note:

> the principal amount of Six Million and Eight Hundred Thousand Dollars ($6,200,000)

Is this a gross mistake? Or am I missing something ?

No, this is what's termed an "Original Issue Discount" in debt parlance and allows for a lender to earn interest without a cash coupon on the loan. Basically they give them $5mm, but the "par value" of the loan is $6.2mm. So MP actually owes $6.2mm, but only got $5mm in cash up front.

I think they were referring to the "eight (2)".