String a woman along, and then ghosting her.

This is something that happened to me, and I just wanted to know if is normal, and get people opinion on why a man would this. I met a man and we hit it off, we are both in our 40's. We both decided that because we have such busy schedules, it would be better to be FWB. Things were great, we had some dates, fun bedroom tome, and hung out together now and then. Then I noticed he started becoming distance, and he always has an excuse, he always had a situation suddenly come up. After a while I finally asked him if something was wrong. I plainly said, if you lost interest or found someone else, just tell me. I said, I'd be sad to loss your friendship but if you feel you want to move on, it's okay. He said he was sorry for being so busy, and it was just one thing right after another. He said things would be back to normal soon. I said okay, and that was the end of the conversation. Then for the next couple of days he texted me, and chatted like before. He still didn't make plans. Then, that was it. No more messages, no more calls. This is what confuses me, I don't mind if an arrangement doesn't work out, that's life..... But why string me along and then ghost me? When I talked with him, I wasn't crying, or yelling, or freaking out. I just talked to him and told him how I felt. I gave him, a clear and easy "out" to our relationship. So what the heck? Did he want to keep the relationship , then change his mind? Or what? Ideas? Comments?