We already know that it was not a shrewd investment. Even if btc goes to $100k tomorrow, then he should have sold the house for $ and purchased btc today. Then he would achieve a return more than 3 times greater than what he would actually get.
It is hard to buy at rock bottom and sell at the all time high, if you buy early and do x100 it is considered a good investment.
and that is why it is called rock bottom, because price hardly could move once it hit rock bottom anyway, anyway bitcoin could be worthless by tomorrow, so we never know
We will know if it was 'rock bottom' when we will have go up significantly in price and for a long period of time.