Sounds like the people working on it had no business doing so.
Honda has told us oil pressures for the transmission on several occasions in several different publications, engine oil pressure is listed in the manual in the Lubrication section.
The PCM only knows what oil pressure is at the oil pressure sensors in the clutch cover, it doesn't know what pressure the engine side is receiving but will shut off if the transmission oil pressure is missing.
Any technician worth their salt could tell the clutches were slipping without ever removing any of the back of the engine. I can also see some idiot has used sealant on the rear spacer as well.
These machines are going on 10 years old now and anyone whose had any experience with the transmission system in one should be able to repair them very quickly,