BA/Comair won't check a bag through on an international connection in CPT

[beardoc]

First time in a while that I have had a dispute with an airline. I had two bookings, one for British Airways BA6414 from Cape Town to Johannesburg, and a booking on QANTAS QF64 from Johannesburg to Sydney which had previously been linked and therefore was on the one booking reference. Went to check in at the check in desk and they refused to issue boarding passes for Sydney and insisted that I had to collect my checked luggage and recheck it at Johannesburg. Knowing what a mess that process can be, and knowing that there was an interline agreement between BA and QANTAS, I had to insist that they did. Eventually they agreed. Turns out that the issue was that BA/Comair actually have a policy where they refuse to check bags through because if the bags go missing it is them that pay for the costs of the bag search, so they routinely refuse to check bags through unless they have booked the flight themselves.

I thought this was pretty poor form really, and flies in the face of the interline agreements.

Has anyone else had this problem before where an airline refuses to check bags on linked bookings with the oneworld alliance?