It is always sad to hear of such a loss.
But in my opinion, we yet have little idea about nor do we achieve much speculating on the cause of Joe's accident.
Compared to the loss of Steve Fossett and many others, the search for Joe took very little time. Steve was using an ELT, Joe had modern tracking devices. We wish they were all still with us, but at least for Joe it was no longer a mystery for friends and family.
From personal experience with SPOT1, SPOT2, InReach and APRS, InReach SE works well on the parachute harness. SPOT works but just doesn't compare. APRS works well in the baggage compartment, even using a horizontal "stubby" antenna surrounded by a mostly carbon fuselage. No unit is absolutely perfect, but nor is cellular data, FLARM, many pilot's vision/scan, etc.
Any parachute rigger can construct a SPOT or InReach pouch and a hard point on the riser cover of a parachute harness that will not interfere with finding the ripcord or parachute deployment. The cost for those is only about $50, so no need to improvise/compromise.
In the big picture, InReach is not expensive. As mentioned earlier, the amateur radio license is easy to get too.
Jim