The little Haflinger that bolted with me (He had going through gate issues...and lo and behold we walked through a gate and BAM off like a you know what) lol, I kicked him, leaned back, I had tried the one rein stop, everything, he was completely GONE, and it took a huge black freisan/tb in his way to stop him.
I think after that they worked on his gate problem.

The Haflinger I bought will stand dead still while you mount/dismount, he wont even move until he gets the cue to go, you can just hop on and sit around all day if you wanted to, and I tried the hop off thing, he stops pretty darn well. My friend slid off his back and fell once, he took 2 strides and stood perfectly still and waited for her to go get him. He even turned his head and I swear it was like he was saying 'Well now what'd you go and do that for?'