Thanks all for consideration and replies. Yes we are aware normally the glass would be the OC responsibility, but considering the owner has made unnaproved alterations to the glass door by installing this doggy door therefore compromising the safety,strength ,security of the floor to ceiling glass door bla blah blah seems unfair that the OC should cop the expense. How on earth are we to know when people do these alterations and put the appropriate responsibility bylaw in place? Unlikely the thief would have been able to break the glass door if there was not a doggy door conveniently located to remove! Anyway, thankfully the person is safe and we pay for the door perhaps with misgivings. Still, not right. 
Cheers and Happy New Year.