That is odd... Unless he's specifically referring to "newbie gains" or is talking about the perfect situation where you are taking in exactly what you're burning and need to build with instead of just ball parking a 250-800 calorie buffer.
Unfortunately he didn't say it within any context, just during the course of his summary. During the other topics he always specified that his recommendation should be taken with our own perspective and goal in mind. Is the goal to just get good results (ex: the average joe), or to get the absolute maximum results (ex: a bodybuilder)? He says that the basic rules that we all should follow, such as taking protein on the lower end of the range (.7g/lb) will give us about 80% of the results. Going higher in protein intake (1g/lb) will give us the remaining 20%. So basically doing the minimum will give you most of the results, while going the extra mile will give you more results but with diminishing returns. So my guess is maybe that applies to that statement as well. Perhaps being in a surplus is like going that extra mile and getting the absolute maximum results you can get, but if you aren't in a surplus, you'll still get most of the results (the 80%), just not the maximum (the remaining 20%).
Thanks again for the video. One of the most informative I've seen and from an actual expert in the field. Although each part is over an hour it's well worth it. This is the first video that actually convinced me that I may not need a ton of protein. I'll play it safe and still stay over the 1g/lb max he suggests, but based on his info it definitely doesn't seem like I need to be consuming 220g when I weigh 157bs.