  {Context} Recent investigations of the white dwarf (WD) + He star channel of
Type Ia supernovae (SNe Ia) imply that this channel can produce SNe Ia with
short delay times. The companion stars in this channel would survive and be
potentially identifiable. {Aims} In this Letter, we study the properties of the
companion stars of this channel at the moment of SN explosion, which can be
verified by future observations. {Methods} According to SN Ia production
regions of the WD + He star channel and three formation channels of WD + He
star systems, we performed a detailed binary population synthesis study to
obtain the properties of the surviving companions. {Results} We obtained the
distributions of many properties of the companion stars of this channel at the
moment of SN explosion. We find that the surviving companion stars have a high
spatial velocity (>400 km/s) after SN explosion, which could be an alternative
origin for hypervelocity stars (HVSs), especially for HVSs such as US 708.
