http://www.rubysoccer.com/game/player_info/158403

This player has the following attributes:

Tackle: 70
Passing: 75
Shooting: 69

However, he is not a midfielder, but a DA. Is this a bug?

That’s ok. When the player is generated we give him a bonus in the main skill, but when multiple positions were introduced the bonus is split between the 2 main skills when a player has 2 positions, so for this type of player it can happen more often than with 1 position players. The thing is, this guy just got lucky to start with a higher passing value :-)