Our internal auditing department found a settlement statement that required a tolerance cure, however it was not given at closing or within 30 days of closing. Should the bank (90 days after closing) send a cashiers check to the borrowers for the cure amount?

We had this happen, and we were told to send a corrected HUD1 statement as well as cashiers check with an explanation

Absolutely do the correction when you find the need for it!
Your audit report goes to the examiner so they're going to see this too.
No way do I want to be left stammering that it was past the 30 days so we didn't cure!
As has been often stated in these threads, the 30 days is the time period where you can correct with no harm/no foul. It doesn't say that you shouldn't correct later. It unspokenly seems to allude to the fact that you could get dinged for not catching it sooner tho.

Thanks for the responses!

The 30 days is only offered as a 'free pass' from a violation...it has nothing to do with correcting the error regardless of when discovered.