What are the differences between Oracle Turing Machine and PAC?
An oracle access to a random oracle can simulate the effect probabilistic TM's have. However, oracle machines aren't limited to using a random oracle, you can specify whatever oracle you would like, to any problem - no matter how hard the problem is, and a TM with an oracle access to it would solve it in constant time.
So, in this line of thinking - an oracle machine can be thought of as a really general extension of the probabilistic case.
I don't know if this answered your question, but I hope I managed to help a little!