Keep in mind how you would handle this situation if you managed a large and well-established dev team with procedures and policies you worked hard on and are proud of. It is not enough for a team member to be fantastic in a solo role. I'd be more interested in hearing from other faculty than I would from the students, who don't much experience actually working with Coward.
His entire job was teaching students, so I don't give a rat's ass about what the rest of the faculty thinks if the students like him and perform well.
Yes, there could still be confounding factors. He is seen as an enjoyable lecturer, and students who care about their classes enough to select the better lecturer might be better students. But still.
If you want to continue the analogy to software engineering, the modules he's producing are students, and they are meeting their specifications (later performance) quite well.