There have been numerous interpretations about what went wrong with Soyuz 1.
Several things are transpiring and make sense.
His flight was hastily prepared and they knew (not only because it was the first flight of a new vehicle) it was extremely risky.
A Soyuz 2 (with Bykowsky, Yeliseyev and Khrunov) was ready to join with Soyuz 1 if the latter was in good condition once in space.
It turned out that one solar panel did not deploy, that there were sensor problems, communication problems and the spacecraft had to be manually stabilized now and then.
The ground decided to cancel Soyuz 2 and land Soyuz 1 after just one day.
The descent phase started alright (even if it was a ballistic re-entry).
Some sources say the capsule was tumbling when the drogue parachute was released. Anyway, the drogue parachute did not in turn release the main parachute because the latter had gotten jammed in its container "flattened by the excess pressure inside the capsule compartment". According to some versions, a back-up parachute was released but got caught under the swinging drogue shute and also failed to deploy.
The speed at impact varies from 100 km/h to 100m/sec.
The main parachute never left its container because it didn't have enough room to deploy.
Had there not been problems in flight, Soyuz 2 would have been launched, Yeliseyev and Khrunov would have transfered into Soyuz 1 (Soyuz 4 and 5 did just that) and all three would have died and Bykowsky too, BTW, as it was discovered that the Soyuz 2 parachute would also not have deployed.
The in-flight problems were never life-threatening; it's the parachute not leaving its compartment that caused the tragedy.

He wasn't in touch with the ground when he realized he wasn't going to survive and this happened at the very end of the flight. So, talking to his wife and cursing against Brejhnev were merely added stories that only threw more confusion to the event.
But it's true it's not completely solved.

Raoul