In recent years, planar magnetrons used for deposition have been increasingly operated in pulsed, high-current regimes. These dense, transient plasmas present a challenge for both simulation and diagnostic measurements. In this communication, a recently-developed incoherent Thomson scattering diagnostic is applied for the first time to give time-resolved measurements of electron properties in a high-current pulsed argon discharge. From plasma initiation to the peak of the current ramp, an increase in electron density of two orders of magnitude is observed. The electron temperature exceeds 10 eV almost instantaneously (only 3 microseconds into a 60 microsecond pulse) and saturates near 3 eV during the pulse. The high diagnostic sensitivity gives access to electron properties from discharge initiation, during the current pulse ramp and decay, and even into the plasma afterglow phase.