Yes. The author contacted the actual Louisiana attorney general with whom Abagnale claimed to have worked. The AG said Abagnale never worked there. The author also dug up the records of the bad checks Abagnale wrote against the airlines. He was a clever forger, and the airlines went after him, but the total bad checks came to only around $1200. And Abagnale was busted by a small town cop after passing one of those checks. The FBI didn't even have him on their radar.

All his exploits were small-time cons, and he often got caught. The author does a really good job of documenting all this with primary sources (arrest and prison records, etc.), secondary sources (news articles from the 1970s) and with interviews with people who were actually with Abagnale during some of the supposed exploits in the 60s and 70s.

Overall, it's good, thorough journalism. I wrote a brief review at https://adiamond.me/2021/03/the-greatest-hoax-on-earth-alan-..., but the WHYY review is more thorough.

And, BTW, I loved the movie. As author Logan points out, one reason con men can con is because people would much rather believe an exciting romantic story than a mundane and disappointing one.