So if he was in FL for more that he was in IL and made more in FL than IL, then FL would be his tax home?

Home is basically where you intend to return after you have finished what you are doing in that other place. There are a myriad of determining factors - driver's license, home ownership, family, car registration, voter registration. Here is a quickie from Illinois https://www2.illinois.gov/rev/questionsandanswers/pages/369.aspx California has a whole book.

https://www.irs.gov/publications/p463#en_US_2018_publink100033754

Thanks guys! It seems to be more of a pain than I thought.

One more thing......So Illinois will tax FL income since he was a resident but I don't need to file a FL return since they don't have income tax?

Correct.

Thanks again!!