My abf was JUST like this last week. I could've sworn that he was using again - instead of going to his meetings like he said he was. Had that smell, the look, the whole nine.
Found out - from his sponsor (the Nazi he is) - that he is clean. (Sponsor had him take a test cause he was seeing the same things.)
Upon further investigation - from the sponsor not me - he was just having his 'itch' to go back out. He was struggling with his demon and, according to him, it was close to winning.
I'm not trying to suggest being in denial. You know your husband better than us and Japic05 has it right - if it looks like a pine tree...
Be prepared ALWAYS just in case.