The single vs 2 argument works only if you assume an aircraft failure. What about hitting the ground whilst trying to survey it from the air? A medical emergency, etc, etc, etc.
A standard ELT works as advertised only 10 to 20 percent of the time. Fact
If he is alive, there is a fair chance the ELT would have been manually operated and every ELT that I have used has worked fine under those circumstances. The odds do not look good.