He invested to make a long term profit and he may not have sold at 400K$ while he was having costs to maintain the house. He has no cost to hold BTC.
Unless he was living in that house(and even that ) I don't think the annual cost of maintaining a house would be that much a factor(depending on the condition of that house and where it's at), he could always rent it to offset that and made some money in the meantime.
In order to make an actual investment comparison we need to also know the potential profit from keeping the house (though rents e.g) and t how much the property value have changed since then.Do we have any of that info?What we know is the current price of bitcoin and from that we know that he have lost money.