Dumb Waiter: Thieves Tracked by Facebook Dismissed

Thanks to a student of mine for sending me this story about a group of people who had an expensive dinner at a restaurant in Melbourne, and then bolted without paying the bill.  Unfortunately for them, the restaurant owner found their stupid faces on Facebook and tracked them down.  He then called their employer, a competing restaurant and passed along the story.  The thieves’ employer then dismissed them for stealing from another restaurant, even though the individuals had returned to apologize and pay the bill.
In Canada, can an employer fire someone for committing a theft off-duty?  Firstly, provided there are no human rights issues involved, a non-union employer in Canada can dismiss someone for any reason, or no reason at all.  All it has to do is give the employee ‘reasonable notice’ of the termination.  So, if the employer gives the thieving employees notice, it certainly can dismiss them.  
The trickier question is whether the employer can dismiss them without giving any notice — for cause.  The answer depends on whether the theft substantially injures a legitimate business interest of the employer.  I think on these facts, the employer, a restaurant, would have a pretty good argument that the decision to steal from a restaurant in the same city caused it substantial injury. The manner in which the thieves were caught — on facebook–attracted media attention, and it could harm the employer’s business to be seen to tolerate its own staff robbing from restaurants.  It tarnishes the image of the restaurant by making it look like it hires dishonest staff.  If the employees were responsible for handling money or serving customers, the injury would be most clear.
What do you think?  Should the restaurant employer of the thieves be required to give them ‘reasonable notice’ of their dismissal, or is stealing from another restaurant  grounds for dismissal with cause, without notice?