If he doesn't have property tax built into his mortgage payment, it would mean that he needs to come up with $2k by the end of the month. He's not exactly smart with money. Also, you can get a decent estimate on his money with the few times he's alluded to how much he owes. He's said before thousands of dollars, but not more than $10k. So take $5k and assume the highest possible tax rate for WA state (1.5%), which would give the lowest possible income. $5000 / 0.015 = $333,333. He owed tax from half of 2014, 2015, and 2016. So he's got somewhere in the neighborhood of $100k annual income. Even if you want to include a fudge factor of $10-20k, he's still making $80-90k annual.
I've also done a ballpark estimate on his annual expenses elsewhere (probably the Savings and Loan thread), and it comes out to like $7k a month. And that's before food, unexpected expenses, and game purchases.
He could very easily be in financial trouble or on the brink of it, but I don't buy that it's as bad as he claims.