Yes, "when it was orally pitched to me" means that something was explained or proposed to you verbally (rather than in writing). The phrase "orally pitched" suggests that someone made a proposal or presented an idea in spoken form.
However, it's not a very common everyday expression. People might more commonly say "when it was pitched to me" or "when they presented the idea to me." The word "orally" is used in more formal contexts, such as legal or academic situations, so it could sound a bit formal or technical in casual conversation.