Changing mind after rejecting a job offer
People change their minds. This is a reality. 

It would not hurt you to ask if the position is still open. Explain the situation and ask if they would still be interested in hiring you for a post-doc. Be warned that it is very possible that they will just write back and tell you that they are no longer interested or that the position has been filled.

Be prepared to explain why you suddenly want to pursue the post-doc that you previously turned down. Be careful to avoid sounding like you have issues with commitment. Do not speak ill of your industry work. 

In the end, even if the professor rejects you for the post-doc, I highly doubt that it would cause you further issues. It is not like the professor would write to all of his/her colleagues and inform them that you are looking for a post-doc, and that they should blacklist you. 

One last thing I will add: Maybe do not quit your job in industry quite yet. It is much easier to apply for post-docs when you have a steady pay check than when you are unemployed. This will allow you to make decisions without having to consider immediate money concerns quite as much.