Someone's daily challenge score was over 100,000?


This might not be much of an actual bug report, but it’s hard not to be skeptical about this.
This past Tuesday (2020-10-20), ArghaGhosh7499 won first place on the leaderboard for the daily challenge, a Cairo map in Normal mode, with a staggering score of 110,952 passengers.

Note that the second-place score was 2687; ArghaGhosh7499 blew everyone else out of the water by two orders of magnitude. The same user has continued to come out on top in the two daily challenges since, albeit with less outrageous scores.
Also, oddly, Argha is listed on the general leaderboard for Cairo with a score of only 2500, placing fifth, and the six-digit score is nowhere to be seen.

However, the latter quirk is not limited to Argha, so there’s something else going on. I’ll expand on that later; I’m getting tired of typing on mobile.
Anyway, how is such an astronomical score possible? Was there a glitch or hack involved, or was it completely legitimate? If the latter, how on earth did ArghaGhosh7499 do it?!?

Edit: Forgot to mention, I observed this in Mini Metro for Android, but I doubt that the platform I use will be very relevant.


Also odd: Argha has unusually high scores in the top 10 leaderboards of many cities and a score of exactly 2500 on many others. In fact, every leaderboard that doesn’t list Argha is a leaderboard whose scores are all above 2500, making it seem likely that Argha’s score is always either unusually high or exactly 2500.

Either something really fishy is going on, or someone is extremely skilled at this game.
I’d love to elaborate, but I have something to do that will keep me busy for the next few hours.