It appears to have already been assumed they are.
Should be very easy to prove they were going to buy a house, don't you think?
Maybe. You can't really prove you were going to do something you never actually did.
"could easily die waiting for his day in court
Not familiar with the law, huh? The federal government has 90 days to take action.
Take action, or actually resolve the case?
These forfeiture laws were written by regulators and bureaucrats. What these people have done is to attempt to live their lives and conduct their affairs out from under the watchful eye of those bureaucrats and regulators, and for that they are going to have their money taken. The bureaucrats and regulators will accuse them of being drug dealers to mollify public concerns that they are not being treated fairly.
They were going to buy a house. Fine. Which one?
Whatever. It's a moot point. An update to the story confirms they were drug dealers. Now the asset forfeiture will be criminal, not civil.
You are so naive, it's embarrassing.