While I'm probably a little naive, it also just wouldn't occur to me that he was deliberately looking stupid. So my assumption would have to be that he actually thought this was true for some reason. Possible reasons:
1. He misheard something or otherwise confused OS/2 with something else. DB/2 for example. 2. IBM had extracted some bit of technology derived from the OS/2 lineage and were pitching this as the latest and greatest thing.
On this assumption, flat out contradicting him would make him look stupid, and at least be a little rude. So to me this says more about his character (VC who plays games - sounds unpleasant) than it does about that of the people he says it to, other than that they're prepared to dissemble a little to keep an investor happy.
Me, I'd say "Really? Are you sure!?" but I'm not looking for cash.