I agree with him. Unfortunately, most managers think this means they are supposed to have status meetings, or as one of the respondents said earlier, walk around asking if you're done yet. As a gross generalization, managers do not understand how to ask for status information, and how and when to disseminate it. The other things managers tend not to do is understand the deviations from the plan. Some managers believe the plan is engraved in stone, but in reality, the plan needs to be a living, updateable document.
Some managers use that continuous updating as an excuse to slip a week every week.
They understand the tradeoffs of spending more or less time on a given task, and if things are getting late, to assess tradeoffs and risks, and choose a plan of action that still meets the corporate goals. There are many, many sources. For books, the first three authors that come to my mind are Gerald Weinberg, Roger Pressman, and Watts Humphrey. I can think of four you might consider. You will probably need some training, a consultant or both to apply it.