jneutron touched upon it being neutral related,
This is fascinating, and often mis-understood effect.
I would essentially guarantee .... that a neutral was opened up under load, thus excessive voltage greater than 120v was placed across some items for a period of time. It wouldn't necessarily have occurred at the panel, it could easily (and most likely) have occurred at a junction box, or a receptacle or switch box whereby joints were being made. It doesn't matter where it happened, they did it.
Surge from the power company .... yeap, right ...
The contractor is liable, it would only take a brief moment for this to occur, and often occurs when an electrician is making up a neutral joint (adding another wire, etc.), and the return path to the panel is opened up, thereby the low impedance path is gone, yet another route is availed to the via the other phase.
Now, for a brief period, there's series connected loads instead of the typical parallel connection. The least robust device gets cooked, the reason being the entire 240v is now dropped between the two loads. The smaller the load, the larger the voltage dropped across it. The larger the load, the smaller the voltage dropped across it. Hence, the damage occurs to the small, modest devices.
Then, the neutral joint is made up the manner the electrician intended, and the circuit is back to normal, however the damage is already done.
I'd be glad to detail this further if need be.
I hope this helps.