Hang in there -
Banks employ people - and people make mistakes.
I would personally sit and compare entries, side by side, with the bank statements - starting at the last time we agreed (balanced)
Sounds like the 2 of you have overlooked the problem so many times that it's habitual - a new set of eyes may just look it over, and say "Well, there's the problem - right there in plain sight"
I HATE when that happens
