Double or False Double?

[Eastshire]

The foul, of course, is what makes the ball dead in this scenario. There is a period between the foul and the whistle being sounded where the ball is dead but only the calling official is aware of it. However, any foul during this period is technically a foul during a dead ball and should be dealt with as such.

However, given the definition of a personal double foul is "two opponents commit[ting] personal fouls against each other at approximately the same time," it would be impossible to have a double foul unless the fouls were committed at exactly the same time as the second would always be during a dead ball and thus not a personal foul. Therefore, I believe the expectation is that a situation such as the OP, where the second foul occurs before the whistle to announce the first foul, should be considered with the confines of "approximately the same time" and treated as a double foul.

So, although it seems the official incorrectly called the second foul a technical instead of a personal foul, the end result, double foul enforcement, appears to be correct (excepting the technical foul hanging on the second fouler).