TLIK: “When there is a suspicion of molestation, one could easily argue for a shailoh to be asked. Why? Because it is not happening at the moment, and the delay in asking a Rov is not occurring while dangerous activity is happening. When danger is happening in the present, even a sofek sakana, one must act immediately.”
TLIK (and everyone else) – In this case, it is not happening at the moment – it is an ongoing situation. It happened 3 weeks before and then again the night before.
No one’s life is in immediate danger. He never stated that he was concerned that someone’s life was in danger and that IMMEDIATE action must be taken. He is even doubtful if there is any physical abuse going on at all.
Furthermore, we are talking about adults, and the OP mentioned that he is thinking of having his wife go speak to the wife. So apparently the wife is not dead or dying if he thinks that his wife can speak to her. He also apparently has not seen any signs of physical abuse.
He has had ample opportunities to speak to speak to both the husband and wife since this happened. He is clearly not personally afraid of the guy and can go over himself to see if he is abusing his wife.