if you watched "Supermilers" documentary (shot in late '83 if I'm right) it's apparent that something's wrong with Ovett. Coe is only one year younger than him, but in the movie, Ovett looks at least 10-15 years older than Seb. Bad teeth, bags under his eyes (which suggest some intestinal problems) and overall look. He went 15 years older in the space of just two or three years. I don't know if he was drinking or smoking, but his food regime is suspicious.
Ovett from 1977 to 1981 was one of the best ever middle distance runners, but after that just an also-run. Yap, he had some fine performances after that (WR in '83, string of 5-6 good races in '86), but it was not Steve Ovett we knew.
In '84 he still had good speed (as his 1:44.81 in L.A. semis was his second fastest ever 800m time), but he was perhaps too greedy and it would be smarter from him to skip 800m and 4 brutal rounds and concentrate on 1500m solely. He would not beat Coe, perhaps not even Cram, but bronze would be great. In the end, as one of the greatest milers in history, he has only one bronze from 4 global outings over 1500m. Pity.