This take is awful because it completely absolves the lender of a lending decision that he alone made. And to boot, he just arbitrarily assigned the loss the newest player in the game. I can't believe you are defending this in the slightest.
I don't even think this approach (making the winning players eat a loss caused by poor banking) is appropriate for honest mistakes.
I have a guy who plays in my tournament league who is physically incapable of being a responsible adult. Let's call him Aaron.
He can't sit down for 10 minutes without having to go smoke a cigarette, use the bathroom, get another beer, talk to the random person who just showed up, whatever. After he busted early from one tournament, he got a cash game started and was running the bank because I was still in the tournament and no one stopped him. (Cheeseburger stakes, $20 max at a time.)
To say it was amateur hour is an insult to amateurs. Aaron's idea of managing the money was just throwing it willy-nilly into a big, disorganized pile in the middle of the open chip case. Dude wasn't even at the table half the time. He'd wander off for 15 minutes at a time to do whatever, repeatedly. If he was away, he'd let everyone and anyone help themselves to chips on the honor system.
Usually I would take over the bank when I'm out of the tournament because I run all the poker games. I absolutely refused to do it this time. I just said if this is how he wants to run bank, he can run it all the way to the end, and if it's short, he's eating the shortage.
After I sat down, a couple players loaned each other money to buy in. Like, actual cash to put in the purse, not promises. Aaron watched this with interest and said, "Oh, we're doing loaners now? Okay!" Then he proceeded to issue himself a $20 rebuy from the case with no cash exchanged. I asked him, "Are you going to cover that?" "Uh, yeah," he said.
I wasn't planning to let him pull another one, and thankfully it didn't come to that.
When the game broke and it was time to balance out, he came up about $20 short (beyond his self-issued loan). Thankfully he had won a bit during the game, so he was able to cover his loan and the shortage. I would never have compelled or even asked anyone else to cover it. He chose to act as banker, and it was entirely his fault the bank was short. (I forbade him from ever running bank again after that.)
This is an extreme example, but it's illustrative: bank errors seldom happen with a competent, responsible banker, and that's the kind of banker a game should have. If you're not that, don't run the bank, and certainly don't issue credit to anyone.
But if all that fails, and you end up with a banker who's not up to the task, or who wants to make sloppy credit arrangements with compulsive gamblers,
it's entirely on the banker because the banker is responsible for all the decision-making and all the actions. Players, whether they win or lose, should never be asked to eat a banking shortage unless it's for a truly exceptional reason (like the game got robbed). Shortages resulting from the banker's ineptitude, bad decisions, or bad faith should never be anyone else's problem.