@jaizei There are many threads about Bob here on the forum. Just look them up or ask Cameron to help. He can find them all. It all starts with bonding, and takes years.
After a while of hand feeding a tortoise he starts to think the hand is food. My Bob who loved me dearly thought my hand was food and cost me 7 stitches. He was 15 at the time and no dummy. But any expert on the forum will tell you I am correct. Now I understand Oli is small and not likely to hurt much when he bites. But it is still unacceptable behaviour.