If you try to report for the title then it gets stuck forever in a loading loop. (Side note - Mark Osborne if you see this please don't crash into people after the finish line just because you couldn't overtake them on the track.)
Since were in beta and the number of people trying to join servers is way higher than anticipated, I dont think this function is at the top of the list for the dev team at this time. might be frustrating but right now i think its best to just go with whatever happend until they get the server problem sorted. Once everything is going smooth Ill start worrying about my rating and people that potentially need to be reported.
Just saying that they know there is a problem with the reporting system. They are also trying to keep reports down to just griefing right now through this beta, not racing incidents. Put in a support ticket in the #online-support channel in discord for possible griefing.