A very interesting topic of which I have read very little about.
By coincidence I have been reading a book which is a compilation of peer reviewed papers. A paper therein, authored by Fransjohan Pretorious (2000) deals with the relationship between the Boers and Agterryers.
I thought it was worth quoting here as follows:
"Goieman, who was the Agterryer of Commandant (later General) Jan Crowther of Ladybrand, somehow managed to acquire a Martini -Henry and prior to the battle of Biddulphsberg on 29 May 1900, he took up a position to the left of the left flank without being noticed. When the fighting broke out, his rifle, which did not fire with smokeless powder, made such a cloud of smoke that it immediately caught the eye of the British artillerists. A light breeze wafted the smoke in the direction of the burghers, and to their great consternation, the enemy started to direct their artillery attack at that point. He was told in no uncertain terms to stop his shooting. Crowther caught him with his rifle and ordered him to never appear in the battle lines again. After the battle, Goieman boasted to burgher J. N. Brink about his skill at shooting, but according to the Boers, his bullets in fact hit the ground about four hundred yards in front of him."
Further:
"But there was a core group of Agterryers of unknown number, who displayed exceptional loyalty towards the Boer cause and who still remained loyal to their masters in the guerilla phase. According to J. N. Brink, Goieman, the agterryer in the service of General Crowther, declared that although he had a black skin, he was just as loyal a burgher of the Orange Free State, and the big morena, President Steyn, as were the whites. Charlie, Kalie van Der Merwe's agterryer, apparently watched the battles on the Natal front from behind a ridge where he kept the horses. He shouted loud encouragement to the burghers while rushing around jumping for joy at the excitement of it all. The above mentioned Windvoel who accompanied the Rustenburg commando and possessed his own rifle, could not tolerate Africans who were on the British side. If he spotted one in a British column, he was the first who had to be made to bite the dust. 'They are traitors to their country, my young masters. It is also their land, just as it is ours, and there they are, leading the enemy onto our trail. I shall not spare them.' G. J. Joubert later wrote sympathetically about the faithful Agterryers who came under strain when the war became prolonged and there was constant moving over the railways and through the lines of blockhouses. Nevertheless they appeared to retain their cheerful disposition despite all this. After a time they too could sing the songs which the burghers liked to sing and before long they also learned to imitate the games which the burghers played."
Taken from:
Fransjohan Pretorious (2000). Boer attitudes to Africans in wartime. Chapter six; p. 116-117 in
'The South African War Reappraised ' (2000) edited by Donal Lowry.