Yes, he would find out if Kavan would follow him alone, but it's mostly Van who follows him and she is a very experienced tracker, she knows how to hide Kavan too, at the lake for example.
Now that Kavan has an idea of Gideon's goal, he needs to get his sword to him and project him in a fight against the ancient vampire and his minions.
I really love your idea that Kavan will be able to protect Gideon, and you have every reason to assume this as he did it before. At the moment though, Kavan is still in strangle-your-bloodsong-and-yell at-him-mode.