I've done this on a few occasions and kind of sweated it out. Initially, I felt really bad. But then I found out that my AH's family and friends (some of whom are also in NA) already kind of suspected that he'd gone on a binge; because they'd kind of figured out that when theycouldn't reach him, he's was usually out on a binge. In the years before I set a personal boundary and removed myself from the drama by shutting off all the phones, they'd want me to tell them when he got back home, give them updates, how long had he been gone, where did I think he could be, had he given any sign that he was going to use, etc. It got to be too much for me. I finally told family and friends that when they call him at home and on his cell repeatedly and there's no response: just assume that he's using: and don't call me because there's nothing I can tell them. I don't know where to find him, either.
Before I set that boundary,and said something I regretted, I just would tell my AH when he returned that I'd told family that he was gone, etc. I think in my case, I just got tired of lying about what was really going on with him. Usually he'd be relieved because they'd have time to 'cool down' by the time that he got around to talking to them. He didn't have to face the music, so to speak. My AH is not a violent person, so I never have had to deal with that kind of situation with him when he came back home.
I hope that things work out for you.