Tineya's spear pierced half of the Rider's throat before it inevitably stopped due to the Rider's firm grasp around it. It wasn't all the way through, but it was still more than enough to kill the Rider if he was left alone.
However, he wouldn't die that quickly, and he would still live for long enough to threaten Tineya's and the other two's lives. So, as soon as she noticed that her spear had stopped moving, Tineya let go.
It wasn't even worth trying to pull it out and open the floodgate of blood that was the Rider's throat. Even if she didn't pull it out, the damage was already done, and blood had started forcing its way out of the wound and his mouth.
The Rider knew that pulling out the spear would make him die even faster, but with it lodged in his throat, he wouldn't be able to move around at all. So, he unhesitantly pulled it out and twirled it around before throwing it at Tineya.