The Campaign of 1815: Chiefly in Flanders (1908) by Walter Haweis James, footnote pp. 265-267: https://books.google.com/books?id=cZUJAQAAIAAJ&pg=PA265

It is claimed by the Dutch-Belgians that Chassé's division was used in the final phase of the battle for two purposes (see Loben-Sels, p. 298, &c.) Part of Detmer's brigade was employed to fill the gap caused by the dispersal of three battalions in the front line, and that Chassé himself led his division, and especially Detmer's brigade, against the enemy with the bayonet. That Krahmer's battery came up close to the 1st British Brigade to support the guns in the front line, the fire of which had become feeble from the want of ammunition.

Krahmer's battery was undoubtedly of the greatest value; it was well served, and produced great effect on the advancing Guard. But that Detmer's brigade had anything to do with the final repulse of the latter, or that he ever closed with the bayonet, or did anything more than follow up after the French had been defeated, there is no evidence to show. To begin with, if three battalions were used to fill the gap (quite imaginary) there would only have been three Militia battalions to charge, for the time was too brief to have allowed the deployed battalions to have been gathered in once more beneath Detmer's command. The evidence is quite clear that the right of the 5th Brigade rested on the left of Maitland's Brigade, and the only gap which ever existed there was when Maitland wheeled forward his left wing. It was through this interval that Chassé came.

General Chassé in his report differs from Löben Sels, and says that d'Aubremé was kept in reserve and that Detmer's was led in close column against the French Guard (see de Bas, p. 1205, Chassé's Report to the Prince of Orange). Lord Hill in his report to Wellington, dated 20th Jane, praises Krahmer's battery, and mentioned the steady conduct of the 3rd Division of the troops of the Netherlands under the command of Major-General Chassé, which was moved up in support of Adam's brigade to repulse the attack of the Imperial Guard. Chassé not thinking that he had received sufficient acknowledgment, wrote to Hill on the question, and Hill replied to him that in his report he had not failed to inform Wellington that his (Chassé's) division had advanced to repel the attack of the French Guard. Lord Hill's letter is a very cautious non-committal communication, and can certainly not be quoted in favour of Detmer's having taken an active part in the repulse of the Guard. It is perfectly compatible with the accounts of English officers who saw Detmer's brigade advance—viz., that it took place as the French Guard were retiring (see Major Macready, 30th Regiment, in 'United Service Journal,' part i., 1845).

Loben - Sels makes no mention of d'Aubremé's brigade, which with Detmer's constituted Chasse's division, and for a very good reason: this brigade was on the point of running away, and was only restrained by the English cavalry in rear preventing it, and by Wellington saying, "Tell them the French are running." Not even the most zealous advocate of Dutch-Belgian pretension can claim that d'Aubremé's men contributed anything important towards the victory. There is no doubt, then, on the whole, that the description given by Siborne is an accurate one, and it seems to me that the action of Chassé's division was as follows: The whole was brought up as he suggests. d'Aubremé's brigade was left in reserve. Chassé did lead Detmer's brigade to the front, and it did support the movement made by the Guards and Halkett's brigades, but did not come into anything like the active collision that these two English brigades did. It would be ridiculous to impugn Chassé's bravery, and his example appears to have inspired Detmer's men to a considerable extent. But this was the only brigade of Dutch-Belgian troops that did behave as did the other brigades of English and Germans on the field of battle. The attempt, therefore, to suggest that Detmer's brigade defeated the French Guard has no foundation, and does not really appear to have been claimed for them by General Chassé in his original report on the subject. See de Bas, p. 1205: "I marched with the 1st Brigade, commanded by Colonel Detmer, in close column against the enemy, and I had the pleasure of seeing the French Guard falling back before the brigade." A little later in the report he adds: "At the moment that the Grenadiers of the Guard were attacked and repulsed by Colonel Speelman with a part of the 1st Brigade." This, it will be seen, is not incompatible with the French Guard having retired before the movement of Detmer's approached them. The officers of the 30th Regiment, however, are quite clear this was the case. They state that after the French Grenadiers had retired, and after the 5th Brigade had fallen back behind a hedge, "a heavy column of Dutch infantry (the first we had seen) passed drumming and shouting like mad, with their chakos on the top of their bayonets, near enough to our right for us to see and laugh at them," i.e., through the interval made by the advance of the 3Oth and 73rd and by the wheel to the right of the 33rd and 69th Regiments. The last two had made this movement to fire on the 4th Grenadiers attacking the English Guards. This is the evidence on both sides. If Lord Hill and the Duke of Wellington, who were both present at this time, make no mention of this Dutch attack, if English officers who saw it say that it was not an attack but only a support to the attack after the French retreated, it seems difficult to believe that the part Detmer's brigade took was of a serious utility to the Allied cause. Both Maitland's and Halkett's men, after firing, advanced to the charge, but the French Guard did not stay to meet it. Detmer's men were then seen advancing with their "chakos" on their bayonets, scarcely the attitude they would have assumed if the bayonets were to be used for fighting purposes. The losses of these two brigades are illuminating:—

...................Killed. Severly wounded Slightly wounded. Total. Missing.

Detmer's . .....27 ........52 .............................85 ...............164 ....197

d'Aubremé's. 24 ........49 .............................54 ................127 ....145