This is the business reality of the IPv4-scarce era. Diluted IPv4 is not new to many places and will become common in many more places. Furthermore, it is a calculated business risk. IPv4 services will/have become the 2nd class (NAT444...) services as IPv6 ascends to first class status with e2e restored and more and more services supporting IPv6 (World IPv6 day in a little over 2 week!...).
Diluted IPv4 is one thing. Hijacking space allocated to another entity is another. As long as they keep it contained within their network, it's pretty much up to them to break their own environment however they see fit, but, if they start leaking 7.0.0.0/8 or subset announcements on to the internet in general, I wouldn't want to be them or one of the companies that was accepting their routes.
Don't get me wrong, IPv6 has a long way to go in terms of availability, peering, and application support. But make no mistake, the tide is turning. Rogers is doing what they have to do proactively to stay ahead of the curve of complete exhaustion.
I don't think they have to hijack space from DoD. I think there are a number of other options available to them. They might cost more, but, they also come with somewhat lower risks. Owen