This topic is something the young 'uns might not understand. The new way of running a company only pays someone for tarmacing the drive when they are tarmacing the drive.
The point the Col makes here is one of poor management.
The poor manager looks at the book and says "3 days only". The rest of the workforce take note and remember that whenever they may be in the **** in the future, they will get no support. This will encourage them to look elsewhere, not make an extra effort, despise and deride the company and so on. Huge cost to the company.
The good manager will always see an opportunity to give a lot at (little or) no cost to the company. Here he is losing nothing (the worker is high on hours) but the company will be seen as compassionate, trustworthy, worth working for and will gain respect, hard work, discretion and a favourable nod when others choose an employer.
Well, this is how it worked when I was a manager. And it worked well.