The reason that it was not seems quite obvious from the comments does it not? - and there seems to be common theme which I have pointed out by bolding.
That is has been left to the 11th hour is because the EU has not been willing to move their positions previously - and you know that this yet further evidence that "We will only see movement from the EU.........."
"The EU has dropped its insistence on a 'ratchet clause' which would have formalised the principle both sides should keep up with each other's standards. It's now ready to cater for divergence in the future so long as there are strong safeguards to rebalance unfair competition."
"This is a shift from the EU, which previously rejected managed divergence as too messy and risky for its economies. They worried it would create constant uncertainty for them. It thus represents a fair departure from the EU's opening position on LPF."
"There is a difference between having a commitment to match standards hard-wired into the deal, failure to comply with which would be a breach of the agreement, and a mechanism written into the text catering for a decision to diverge and accept rebalancing measures in return."
"What the sides are now trying to thrash out is how unfair competition would be defined, the process for triggering rebalancing measures, and how extensive they'd be. The EU originally wanted the Commission to have the unilateral right to apply them - hence 'lightning tariffs'."
"That demand angered the UK, and has now been diluted by Brussels which accepts there needs to be due process based on evidence. One EU proposal is for a 'distortion test' that could be triggered by either side. They're also open to setting up an independent arbitrage system."
The EU would have had the UK locked in regulatory chains for decades had May/Robbins incompetence still been what they were facing - take a bow Mr Frost.