Rules and submissions

I’ve noticed some disturbing things about the leaderboard. Some of the submissions seams to break the rules.

2 and 3 place - “One account per participant”
Two “teams” have score from almost the same time period, have almost the same score and first team has only one participant named “Thakshi” when the second one has “thakshi2345”

4 and 5 - “Private sharing of code”
6 and 7 and 8 - “Private sharing of code”
9 and 10 - “Private sharing of code”
Exactly the same score when submissions are made within a very short period:
e.g. 2019-06-04 12:35:39 and 2019-06-04 13:01:57
2019-07-06 13:52:35 and 2019-07-06 13:55:39
It’s extremely unlikely that 2 different people had the same score in the regression task within half an hour.

Does anyone even checking that? I really want to be wrong here but that’s against the rules of the competition.