IIRC, inadequate cure was the root cause of the Deepwater Horizon blowout. Ignoring the required cure time was pushed by one firm against the objections of another firm.
As it turns out (although I haven't read the specs or the contract) it appears the span was assembled "immediately adjacent" to the erection point with components fabricated offsite "some time ago". That would suggest sufficient cure time; however, if significant concrete was added just prior to erection, somebody may have jumped the gun.
I am beginning to agree with others above that erection itself may have compromised integrity of the span in a way that overwhelmed the post-tensioning. Erection was tricky, but nothing unusual. One would imagine they had multiple lasers attached to this 175'(+-) single-span structure during that erection.