Paid the property tax bill from my own checking. $2,180 to fix.
Short version: the IRA owns a small rental, the tax bill came addressed to the custodian, the custodian forwarded it to me as they do, and I paid it online from my personal account because I was standing in line somewhere and it was easier than filing the payment authorization form. $1,240. Then a month later the water heater went and I paid the $380 invoice the same way, because at that point it was just how I'd been doing it.
I knew the rule. I'd read the rule. I just didn't connect a $1,240 online payment to the phrase "all expenses must be paid from the IRA," because in my head paying a bill for the house wasn't a transaction with the house.
Caught it when the custodian's year-end statement showed no tax payment out of the account and I went looking for where the money went.
What it cost: $900 to a CPA who does these, $780 to an attorney for a written analysis, and $500 in my own time I'm counting because it was three weeks of not sleeping well. Total $2,180 on a $1,620 mistake.
Where I landed, and this is the part I'd want somebody to tell me earlier: the fix depended entirely on facts I couldn't assess myself, and both professionals said the same thing about the exposure. It got treated as a contribution rather than the worse outcome, and I was under my limit for the year so it absorbed. Different facts and different amounts get a different answer, and that's exactly why you can't self-diagnose this from a forum post.
What I'd do differently: I'd put the custodian's expense payment form on my phone home screen the day I opened the account, and I'd have the tax bill mailed to the custodian directly with no forwarding to me at all. If I never touch the invoice, I can't pay it.