I'd agree it's low on overall grams of protein (for a male, at least) but he did manage to get the amino acids that non-meat diets usually lack... so it's not a total fail.
The grams of protein are within his dietary needs. Nobody, male or female, needs more protein than 10% of their daily calories.
Most vegetarian diets do not lack sufficient amino acids. Protein needs are greatly exaggerated by "pop science". Iron and B12 are of greater concern than protein in non-meat diets.
Meat is overrated as a source of iron, unless we're talking liver or blood sausage.
Most contemporary diets are low in iron because people don't eat their dark leafy greens, which are, far and away, the best source of bioavailable iron. The OP diet, which is heavy on broccoli, neatly avoids this.
while this diet is high in beans and is okay, most people avoid beans for some reason. which results in many vegetarian friends of mine being constantly low on iron. tomatoes are a great source of this. just dont go for tomato juice to get it. its basically salt.