I see that brisk and dreuj have the same rating but brisk is rated higher. I'm just wondering what the tiebreaker is?

that happened because brisk was #1 before dreuj cought up with brisk's ladder rating.

What Motocross says has nothing to do with it.

The real reason is that the ratings that you see are rounded. The real rating is calculated with 3 decimals and subsequently rounded. The higher ranked player thus has a slightly higher rating, but the difference is less than 1 point.

If (probability 1/1000) they have the same rating with all 3 decimals also the same, I assume it's actually the order in which they joined the ladder that counts (this assumption is because I worked with the program which calculates the rankings myself and if the 3 decimals are the same, the order in which players are added to the program counts, I assume this order is the order of joining the ladder.)