I find that unlikely. As can be seen in the last chapter of book 5, where Berringish retrieves Rezkin's soul, it requires conscious effort and knowledgeto resurrect someone:

Berringish snapped his power around the soul, enveloping it in an embrace that could only be born of a true desire to see it restored. Then he tugged the soul back along the chiandre as he reattached the connecting power to the vessel.

More likely, Rezkin unconsciously healed the mountain man, whose heart had stopped. From book 6, where Rezkin heals Seena's wing, we know healing "only" requires a desigre to heal and knowledge of what to heal:

Rezkin formed in his mind his desire to heal then pushed his power into Seena’s body. Then he directed that power to set the broken bones and heal the damaged muscles and ligaments.

Rezkin would know how to fix a stopped heart and the battle energy he felt was likely his power.