10 years enforcing the "no-fly zone" in Iraq and covering the Yugoslavian "peace-keeping" forces has put a lot of time on the fighter force airframes and engines. Far more than routine training would during the same decade.
I think we've been lucky so far that we haven't had more engine failures. I also thought that the decision for single engine over multi engine was a mistake back when it was made. That was the old F-100 fighter guys as generals.
An F-18 would have made it back, most likely, after suffering a single engine failure. End cost on an -16 vs -18 isn't all that great. Cost difference gets huge when you lose one due to single engine failure though.