I well remember a monitored approach when the FO said "decide", I said "land" and on the taxi-in the FO remarked that after the land call had been made he looked up and saw nothing. It made me a believer.
I see your point but surely you wouldn't have said "Land" if you hadn't seen enough at the time to be able to do so? Maybe, and I mean this in all seriousness, he wasn't looking in the same place. You don't say how bad the conditions were but in Cat 3A, there isn't a great deal you need to see anyhow!