SW Motech Quick Lock fasteners avail at Twisted Throttle
Thanks, those look like they have no markings that'd differentiate from what's there now.
Its the first time I remember reading one of them failing, but I have been wrong before. The rack will stay in place with 3 no problem. Up to date I thought they are bulletproof. Mine have gone through may rough miles, never an issue.
The carrier rack stayed on for the journey back but there was movement, that I'm speculating, resulting in a brief vicious wobble at speeds past 150km/h, heck that could've been it flying off and the case resettling.
No evidence of the fastener failing, only that it is missing.
Without the fastener there's no way of examining if it had sheared. Metal fatigue could've been the culprit or the rubber had deteriorated from elements (I should look at the remaining to be safe), maybe some prick loosened it, or it was ridden too hard for its usage (i.e. abuse). The latter two are the least likely scenarios. This fastener shouldn't need periodic tightening as that's not in its design.
I wouldn't eliminate the possibility that it had failed.