Grafical Glitch when trying to dismount the Minecart with "Right-CLick"

What I expected to happend was...
When I try to Dismount a Minecart with "RMB", nothing will happends
What actually happened was...
When I do this, the Minecart while stop for ~ 0,5 Seconds, and then it is back
Steps to Reproduce
1. Place Minecart Tracks
2. Get into a Minecart.
3. Try to dismount the Minecart with RMB
4. Notice that the minecart suddenly disappears, and then appears again.