Hollywood is notorious for ignoring scientific accuracy in films, so don’t expect anything you see on the silver screen to make sense.
That said, EMP is a different phenomenon than ionospheric disturbance. A “storm” which causes ionospheric disturbance, such as sunspot activity, will interfere with radio waves and wreak havoc with communications. An EMP, such as that produced during nuclear weapon explosions, is a short lived but very strong impulse covering the entire frequency spectrum. The important fact to realize is that electric and magnetic fields can only act upon other fields, charged particles, currents and fluxes. Any permanent damage that arises as a result of EMP is a result of the unexpected and strong change of electro-magnetic behavour causing physical damage. Accordingly, if equipment is powered off during an EMP event, the EMP will have no effect since the electric and magnetic fields will have no effect on non-charged or magnetized parts. Conversely, operating equipment may be easily damaged since a large external disturbance can change the behaviour of any electrical current or magnetic flux.
As regards your specific example, this could be explained if the camcorder was off during the EMP and only used afterward, and the solenoid on the bus was operating during it, and was sensitive to field disturbance which damaged it.
More practically, many common devices, even when not in use, employ backup batteries to maintain things like memory, time and date, EEPROM settings, etc. Just as you might damage these things by subjecting them to static discharge (handling chips without having been grounded), an EMP is likely to produce the same problems.
I can’t see an EMP being produced by a storm, though.