I have now found his service record on Ancestry which says that he forfeited his QSA Medal due to being court martialled. I also found the reference for that saying that is was at Harrismith on 23 September 1901, but I don't have an all areas subscription so can't read it.
Well, a friend managed to help me out with this record. It appears that FM Backshall was involved with another five soldiers who also ended up forfeiting their medals. The writing on the record is rather messy, but whatever they did and I think it's an absence of some sort was protested by all and the sentence resulted in the forfeiture.
33 Sep 1901
Not quite as simple as the five "losing their medals". A look in WO100/125 for the 62nd Coy., I.Y. shows "34207 Pte. F.M.Blackshall" earning clasps C/O/T/ and probably 1901 but the medal roll is marked "No Medal, sentenced FGCM 23/9/01 Forfeit S.A.Medal" As a matter of interest, his address is shown as My?elle Villa, Chapel Rd., Ealing.
However, Pte A.Eliff earned clasps OFS/TV (Cape Colony deleted) and the roll is marked "Sentenced FGCM 23/9/01, Forfeit S.A. medal - BUT the entry has a notation "medal and clasps issued 20/9/1905 to Officer, CRPA ??".
And Pte. Gristwood similarly forfeit BUT roll endorsed "medal and four clasps (COT0102) issued 9/11/05".
And Pte Sage's entry marked "No medal - forfeit"
And Pte Smith S.J. entry "medal issued 26/5/02, invalided 24/2/02"
(There also was a Cpl. Griffiths of 62 Coy., I.Y. who was similarly before a FGCM on the same date who was marked "Forfeited" and "Name Expunged" - but was later issued with the medal and three clasps).
FGCM means "Field General Court Martial" which on active service was and is no laughing matter. My take on what is written on the medal rolls means that, following a later review of the sentences of those FGCMs, some were found more guilty than others of whatever offence it was. Hence the later restorations of the awards to two of those on your list and that of Cpl. Griffiths. Seeing that the Cape Colony clasps were deleted off the roll of the two of your listed men who were reissued their medals, the offence may have taken place somewhere in Cape Colony.
By the way, what is the source of the page you posted earlier?
It all looks a bit messy and I hope this helps a bit.