In the link you posted there are 29 errors, of those 19 were throwing errors (fielding tab shows 150 steal attempts, 113 successful with the 19 errors). There were another 10 errors (bad luck perhaps for a lot of x rolls with 2e7 card) PLUS 8 passed balls. and also some range misses.
....in other words, that T rating gets a lot of play if the arm strength and opponent makeup involves a bunch of steals.