  The massive evolved Wolf-Rayet stars sometimes occur in colliding-wind binary
systems in which dust plumes are formed as a result of the collision of stellar
winds. These structures are known to encode the parameters of the binary orbit
and winds. Here, we report observations of a previously undiscovered Wolf-Rayet
system, 2XMM J160050.7-514245, with a spectroscopically determined wind speed
of $\approx$3400 km s$^{-1}$. In the thermal infrared, the system is adorned
with a prominent $\approx$12$''$ spiral dust plume, revealed by proper motion
studies to be expanding at only $\approx$570 km s$^{-1}$. As the dust and gas
appear coeval, these observations are inconsistent with existing models of the
dynamics of such colliding wind systems. We propose that this contradiction can
be resolved if the system is capable of launching extremely anisotropic winds.
Near-critical stellar rotation is known to drive such winds, suggesting this
Wolf-Rayet system as a potential Galactic progenitor system for long-duration
gamma-ray bursts.
