That's not at all appliable to this situation. If Brigade had a Due For No Reason clause, they could have called the loan in at any time, just like a bank call

That's not at all appliable to this situation. If Brigade had a Due For No Reason clause, they could have called the loan in at any time, just like a bank calling a mortgage due at any time. Even without such a clause, Brigade is owed the entire pricipal and all accrued interest, which is exactly what was paid. There was a payment plan, but that doesn't affect the actual amount owed. This literally was a prepayment. The question is whether this was accidental or not.