Clyde Hutchison missed out on two - he discovered Type I restriction enzymes, but they're extremely difficult to understand because their behavior is stochastic, and as a result also not as useful (his buddy Hamilton Smith, won for Type II restriction enzymes, which are still being used).
He also correctly identified (theoretically) the method by which site-directed mutagenesis would be done, published that, noting that it required advancements in oligonucleotide synthesis, then actually did the experiments in collaboration with Michael Smith, who won the nobel prize. He wasn't awarded the prize himself because it was split with Kary Mullis (who invented PCR). Possibly he was skipped over because Mullis and Smith were well known in the chemistry circles and Hutchison was more of a microbiologist, and the prize was a chemistry prize, not a physiology prize.
He also correctly identified (theoretically) the method by which site-directed mutagenesis would be done, published that, noting that it required advancements in oligonucleotide synthesis, then actually did the experiments in collaboration with Michael Smith, who won the nobel prize. He wasn't awarded the prize himself because it was split with Kary Mullis (who invented PCR). Possibly he was skipped over because Mullis and Smith were well known in the chemistry circles and Hutchison was more of a microbiologist, and the prize was a chemistry prize, not a physiology prize.