glass99,
I was involved in fixing one of those, about 20 years ago. In the litigation, everybody involved in the construction had to kick in a share, with most of the minor players settling before trial, and the insurer for the general contractor was left to foot the main bill.
Some key words in your post tell the story: "famous architect", "condo", "fancy", "dodgy Chinese", "design build".
Your project sounds like it needs a new façade soon, before mould becomes the main issue.
Whether of not the developer bears some responsibility will be a matter for the court, and will depend on the testimony.
Not sure I agree that "engineers should run things". They don't always get it right, either.