The author notes that they used "cheats". Depending on what these do the iid assumption of the samples being independent could be violated. If it is akin to snowball sampling it could have an "excessive" success rate thereby inflating the numbers.
> Jason found a couple of cheats that makes the method roughly 32,000 times as efficient, meaning our “phone call” connects lots more often
> Jason found a couple of cheats that makes the method roughly 32,000 times as efficient, meaning our “phone call” connects lots more often