Upon being laid off, H1 holders lost H1 status already. In short term, he will be OK if he can find a job. Otherwise, he should change status if you have valid visa. You don't want to be caught up by BCIS while he is out of status. you would want to go home by youself, instead of being deported.
BTW, the interview skills are not that important for the position your LG specilizes. Keep trying and he will be settled with another firm in NYC.