bug triplet line collides with fingering

[Marc Mouries]

In this snippet the triplet line collides with the fingering.

\version "2.13.60"
\language "english"

Violin = \relative d'' {
  \times 2/3{d4 a8-4}
}
\score {
   \new Staff { \Violin  }
   \layout {}
}

I know i could use "\once \override TupletBracket #'direction = #DOWN" but 
there are already many situations where lilypond detects collisions and adapt 
the music elements accordingly so i am wondering if that's a situation that is 
not correctly handled or a limitation.

-Marc