Interesting you should zero in one thing, which is factually wrong, when the rest of the report is pretty damning of GTR and the DfT. In short, Gibb is criticising the concept of not working overtime. Additionally, he didn't speak to any staff, passengers nor trade union officials in compiling his report - only the train operating company, Network Rail and the DfT. Make of that what you will.
Nice try, but you've missed by a long, long way.
I make of it that 'The Primary Cause of the System Breakdown in 2016' was the RMT and ASLEF.