Not exactly. Before and during his time at FF, PB was informally involved with YC by dropping by often to chat with startups, and probably in other ways. Saying to him "let's get you involved more and formally" is not the same as seeking out a candidate, because "seeking a candidate" implies that there are a few people available for a position, and you choose one. In the YC case, however, it was probably "either with PB or without PB", not "either with PB or with someone else"