AITA Did I save us, or did I set her up? You decide.

I have struggled with addiction for 23 years. Four and half years ago, I met an incredible I have never loved anyone as much as i love her for this woman and chose to quit because she asked me to. While no relationship is perfect, I relapsed three times during our three years together due to relationship issues. Every single time, she came looking for me and brought me home.

On my birthday, she became intrigued by my past. She asked for stories, so I told her, and eventually, she decided to try it herself.
After three years together, we split up. We spent a year apart before reconnecting and entering into an open relationship. Eventually, we fell back into a pattern of regular use together.

One night, I went to visit her at her place, and we were hanging out in my van. I noticed she had a pipe in her purse, which she said was empty. We stayed in the van for a while, and since I had been awake for a long time, I passed out. When I woke up, a disagreement began over the pipe.

Later, we exited the van and stood in the street. Her back was toward a major intersection, but I was facing it. I saw a Ford Explorer make a turn, and thinking it was a police car, I panicked. I took the pipe to get it out of sight and tossed it back into the van to get it off my person.

By pure accident, the pipe landed directly inside her purse.
She was furious and convinced that I threw it in her bag on purpose to set her up. I tried to explain my logic: if it had been a real cop and they saw a bulge in my pocket, they would have searched us. By tossing it away, there would be no immediate suspicion on our persons. I even told her that if the vehicle was searched, I would have taken the full blame for it.
She doesn't believe me at all. What do you think?

What do I do??