There's a very simple way for both sides to add substance to their claim:

Produce signed-off head engineers' logs and documents. I find it very curious that all Metrolinx can do is resort to name calling, when a professional engineer's statement can make their case.

BBD's shortcomings are well known, but that seems to be a smokescreen for Metrolinx' amateurish and bumbling response.

For an agency that's fumbled so many issues, I think they'd best think carefully before resorting to impugning others so readily.

What's next? Not paying Presto for all the massive shortcomings? Oh, wait, Accenture and others have been hired yet again after all their previous botch jobs.