I assume we're talking withdrawals here correct? Obviously for deposits they'd both be benefitting unless I read everything wrong.
I'm big on the phrase "who is at your window" in terms of beneficiaries on cash withdrawal transactions -- so for example the husband comes in to withdraw cash on that account and walks out....do you know for a fact that the wife benefitted? Unless he mentioned something about the use of the cash during the transaction you have no knowledge that the wife benefitted; for all you know he walked out of the bank and bought himself an $11,000 steak and ate it himself (just illustrating, I know that seems absurd) -- obviously at no benefit to the wife.
Life is like a bicycle. To keep your balance, you must keep moving.