Thanks for the article...
From the link:
If there is insufficient gas produced by the powder (burn rate too slow), pressure behind the bullet will drop excessively. Then, as the bullet's rate of acceleration falls due to bore friction, gases may "catch up" to the bullet before it exits the barrel and produce a secondary pressure event. In the above load we believe the heat generated from initial ignition coupled with a secondary pressure event increased the burn rate of residual ball powder to near detonation.
If I understand this, they are theorizing that the bullet is not under constant pressure past the initial spike, and that due to the 'slowing of acceleration' the expanding gasses then 'catch up' to the bullet?
Not proof of SEE, but interesting theory...