My dad is a civil engineer for 40+ years and had a few of his pretension concrete structures fail over the years.
The designers will always blame loading that wasn’t part of the design requirements, like twisting or “shock loads” during construction...because that never happens, you know.
The support cables don’t appear cosmetic. It is my guess that whoever told them to pull the supports out will be held criminally liable, unless it is a minority or a woman.
But they couldn’t have left that vehicle / jacking system in place for the next year while the bridge was completed. That would have blocked the road for an entire year. I’m guessing that the truss was designed to be self-supporting for its dead load and the tower / stayed cables would have added load capacity to support the live load.