Saw this recently and I have a theory. The character that confronts Luke in the cantina in A New Hope, don’t know his name, but it’s the guy who gets his arm cut off by Obi Wan. In Rouge One they bump into this character in the city before it is blown up by the Death Star.
So, this may mean two things. One, he and his accomplice somehow miraculously escape before the city is destroyed, since they appear in A New Hope. And two, this may also mean that Han and Chewie were in the city at the same time.
The Falcon may have possibly been one of the few ships fast enough to escape, and I theorize that the cantina characters were on it, maybe due to paying Han, or Han owing them a debt, but regardless this may explain how they all ended up in the cantina together on Mos Eisley.
Eh?