I just quit my job today. I was wondering if they could go back over the past few years and do an investigation for alligations that i am sure to come

I work for company that takes care of the mentally disabled. The client I was taking care of was my aunt. Her mother has made numerous comments to family pertaining that i dont do my job by taking my aunt places and doing things with her that she wants. If she decides to tell my boss can they stiil do an investigation even though i have quit. The problem is is that I did in fact do the job I was suppose to but it got to where the clients mother would not give the client money to do the things that she wanted to so therefore it came out of my pocket and so I quit due to not being able to afford it anymore. Even though I had already discussed this with the clients mom but she still didnt do anything about it. So I felt that I was forced to quit. Could there be an investigation of some kind regarding the remarks made by the clients mother? I need to know so I know what to be prepared for. Thank you very much.