Ignoring bank cutoff can be costly
I'd be very surprised if your bank did not meet these standards. That leaves the matter of funds availability. Depending on what time of day your husband deposited the check, it's possible it wasn't included in Friday's business.
A bank will often have a cutoff time where any transaction after that time is treated as having occurred in the next day's business. A deposit late on Friday could be credited on Monday.
The bank also has some leeway when it comes to delaying funds availability -- which is also described in the compliance guide. The delay in funds availability has to be for a reasonable period.
You may or may not have some arrows for your quiver in picking a fight with the bank. My best guess from the sidelines is that you won't be able to find them not in compliance with Regulation CC. It sounds like you were pushing the envelope by writing checks on Sunday for a nonlocal check deposited on a Friday.
However, the online banking system should have been sophisticated enough to warn you of this problem. So, you might have some traction making that argument to the bank's manager in trying to get the nonsufficient funds charges dropped and persuading the bank not to report these insufficient funds incidents to ChexSystems, the consumer reporting agency for banking relationships.
See yesterday's column for more about ChexSystems.