Sorry if this should be in the bug reports, but as someone who used this spell a lot in the old retail. I know for a fact it isn't working for at least me.
If working properly, upon judging a player , cat, travel, ghost wolf, & mounts do not grant additional movement. I use this seal & players still take off. I would like to see this fix as it is a huge part of BG & world PvP for a paladin.
Also, I have not seen the stun proc. That could be due to lack of testing though, I just haven't seen one prof doesn't mean that portion of the seal isn't working properly.