In the 35 collective agreements that I've negotiated myself, I have personally never seen, after a strike or a lockout, that when you're ready to have a contract signed, the employer tells the union, “We're signing this contract, so you vote on it, and after you come back, 25% will not come back to work”. Normally, it's after you come back that you get the big surprise that people are not getting called back.
On April 26th, 2010. See this statement in context.