Mine does it regularly, it's related to lateral-G.
I've been told it's related to pads/fluid but the pads aren't worn much and the fluid is just below max... it's just poor design imo as they haven't taken into account the movement of the fluid due to G-force.
It happens on any long sweeping left-hand bend (same as Fien has found) e.g. a spiralling sliproad, the lights either flicker or come on solid for a period of time, I ease off to see if they're going to go out and they do so after 1-3 seconds depending on how it feels. Also happens if accelerating up a fairly long hill.
Irritating but seems there's no fix as none of the supposed fault conditions are present on my car