"The trustee (not exactly a small entity)"

I've had this happen by Schwab to the point that they sent a nice apology gift. It didn't help with taxes, of course. We removed all of the taxpayers' retirement accounts because of Schwab's error.

"but since he has already taken $29,450, he only needs to withdraw another $25,550"

Oh, wow. From AARP:

https://taxaideqa.aarp.org/hc/en-us/articles/360012329514-I-forgot-to-take-my-Required-Minimum-Distr...

"First: Contact the account custodian to take the late RMD now. Do this as a separate transaction rather than combining it with the RMD that is due for the current year. To have the additional tax waived, the error must be promptly corrected. Do not wait. Also, this late RMD does not replace this year’s RMD. That must still be taken and both will be included in this year’s taxable income."

Which is why I print and send stuff to these bonkers brokers quite often. They're supposed to be licensed; sheesh.