Chinchillas are much like humans (but better) in the way they feel towards different people ... but ... smells play a huge part in how one may react differently to the same treatment.
I avoid perfume or colognes when around my chins. These can be harmful to them.
Always wash your hands and around your mouth before you handle or pet your chin. Lingering food odors can lead a little one to be curious enough to try a bite to see if this new smell tastes good or not.
Sometimes, chinchillas need their own space (much like humans) and you just have to give it to them ... they will do the same for you.
Now, if you are not
properly supporting his legs completely at all times, this might be your problem when it comes to him allowning you to hold him. It is obvious he wants you to hold him, or he would not come to you and put his paw in your hand, but he must feel safe to let you hold him. If the chins legs are not properly supported, he thinks he is going to fall and will not feel safe with you.
I have one chin that is jealous of my husband and me. Hubby can not hug or kiss me in front of her, or she will spray me everytime I pass the cage for the next couple of days. She will allow only him to handle her. We have another that will allow only me to touch him.
Chinchillas definitely have a mind of their own and moods to match!
So, don't worry, it is all normal.
Jo Ann