Nine times out of ten, "bad timing" is just your mind's way of letting you off the hook on gathering the courage to make the approach.
But the one of ten times that it truly isn't the right time or place, you just have to let it go and remember there are a sea of women out there and you'll find another to talk to very quickly. Besides, it isn't like you were guaranteed a date with that one anyway.
I used to make the "bad timing" excuse in my early cold approach days. After studying about it a lot, I decided to make a rule for myself that for a month, I would do all my cold approaches regardless of the situation or circumstances that didn't seem favorable (with one exception and that is I don't mix business with pleasure, so if I'm at work, no approaches). I found most of my "bad timing" excuses were made for situations where I would be totally on the spot in front of a captive audience, or even a hostile audience. For example, one time I saw an incredibly attractive woman walking in a mall so I turned around to go talk to her and just before I got to her, she reached her destination which was a tiny little cosmetics shop. There were FOUR young, beautiful women working behind the counter looking bored AF and no other customers in the store. That's a situation sure to provoke anxiety in the best of us. But I walked into the store and started talking and flirting with the girl while the employees just sat there and watched it all unfold. Approaching a woman at a bus stop or train platform with a few other people waiting there is another situation that can provoke anxiety.
This may surprise you but not once, ever, have I been laughed at, ridiculed, or had anything negative directed at me from onlookers after cold approaching a woman and having an interaction with her. That's not to say it will never happen, or that you should be worried about it if it does, but due to our biological programming when it comes to clan-thinking and safety, we tend to be far more worried about negative outcomes in these situations than is the reality. In fact, not only have I not had negative comments or looks, I almost always get the opposite. Even old ladies look at me and smile and most guys just look at me like, "damn dude, wish I had the balls to do that." Again, not that you should care one bit what strangers think of you - I am using this to illustrate how scrambled our brains are about talking to strangers and how far from reality the fears are.