Imdi - That's such a completely bogus excuse on his part (gee - you TALKED to a guy? For 2 weeks? While h was ignoring you? DUH!).
It really makes me wonder if this is more a case of projection. Did you ever figure out if H actually had something going on with OW? This behavior just seems like the spouse who actually cheated, but projects onto the other spouse by accusing THEM of being the one cheating. It wouldn't surprise me if you found out he had had an affair, and that his guilt over the lie is keeping him from reconciling.