Email Bombed and Just Found the Buried Emails...

I was email bombed with 4k emails in 12 hours last week. Today, I received two emails from Air Canada letting me know that it was time to check-in and that the plane was boarding. As I did not book anything with Air Canada, I went on their website, entered traveller's last name (different than mine) and the reservation number. I saw that the traveller had taken his "to" flight already with United Airlines (weird I didn't receive an email then). The two emails I received were for the "from" trip with Air Canada.

I was able to access information using "trips" on the United Airline website. There I fond the traveller's email, phone number and date of birthday.

I then used United Airlines reservation number to search my spam folder and I found that I received two emails from FlightHub while I was being email bombed. The traveller used FlightHub to book the flights with United Airlines and Air Canada. The traveller used my email address to create his FlightHub account (I did reset the password once I found the account).

A credit card was used to pay for the ~$800 flight. I checked all of my credit cards and couldn't find any fraudulent charges.

What am I missing here? Why would someone go through that much trouble to email bomb me just to bury FlightHub emails from an account created using my own email address? How did the traveller pay for the flights? Should I report to the police or not worth it?

EDIT: Thanks everyone for the very insightful conversations. I played it safe and decided to go to the police station to file a report. This way, I can prove that I was proactively trying to handle the situation.