Metrolinx said owners are compensated at fair market value for properties, based on appraisals conducted by external accredited appraisers.
That's not how that works. They are not selling their homes by choice, they are being forced out. Metrolinx owes them the maximum possible value for the properties as without them the project can not be completed.
Not to mention there are technological answers to this problem. They can lower the line, move it towards the center of the road surface, use a more expensive process that reinforces the tunnel more as it is bored or just pay for any fucking damage they do to the existing houses if and when it occurs.