Lizzie, “is there any come back on the owner who did the renovation without approval”. Here is an option before getting heavy. If the unapproved work was the same as the approved work, you could propose to amend the by-law and approval for the approved work to cover the unapproved work as well (or perhaps anyone wanting to do the same) on condition that the owner who paid $1500 is reimbursed half their costs by the owner who proceeded without approval. You could put this suggestion verbally at first to see what their reaction is.
You could suggest that the committee could put the proposal in writing if they are agreeable. Alternatively, the committee could write them a letter requesting that they do the whole process for retrospective approval, which would be on the owners corporation’s records and consequently could be found by any potential purchaser of the unit. Purchasers and their banks might be wary if they discover that the unit has unapproved alterations.
So, play nicely and it costs $750. Be difficult and it costs $1500 or potential difficulties with any sale of the unit they might have in mind.