Yes. All of us focus on the part which adds the item rarity compared to other samples of its type. And fakers focus on those parts too. Perhaps a collectioner must behave like this: if a collectioner's experience is not too much and can't exactly determine the offered item is fully authentic or not, he must just decide if the item would look to other people as much convincing as it looks to himself or not. He must depend on his experience just that much. If the item doesnt look really suspicious to me, it means it would not look suspicious to most of other average collectors who are in vast numbers too. So I would stay on the safe side, would be able to resell it without loss or with some or more profit when I want to. That is the main point of Ian's story too I think. The dealer considered that of course not in good faith-most dangerous character for collectioners-, but he knew it was authentic enough to convince most collectors, and the collector which bought it thought like I wrote above. He can still resell it to someone, and I am afraid there are so many pieces like that circulating in market.
The real problem starts if a real expert checks your new item and explains it is a fake. So you must hide the fact and lie to others, to be able to get rid of the item which you will immidiately start to hate and you will not stand to see it anymore. While offering it, what will you tell your friends or any potential customers if they ask you about its authenticity? Will you be honest or not?
So,simply never show your already owned items to real experts for your brain and soul comfort. Do it in advance if you can, or hide forever.
