C100 Driver you are right about Plan Continuation Bias and you do present a viable option in taxiing back to the terminal.
However a properly considered risk assessment of the takeoff was another option. Your employer and the passengers require you to depart only if you have done that.
Clearly this crew did not just taxi out and go without making that risk assessment. That's what the four stripes are for.
The argument is all about others second guessing that decision without all of the available information. None of the witnesses can really compare what they think those conditions were to the conditions assessed by the crew. They would have had to have been on the flight deck with them or in very close proximity to it with the same level of experience and some qualifications to go along with it. All CAA's witnesses don't cut it in my opinion. They either were there and not qualified or qualified and not there.
If this guy gets convicted it will be a travesty.