[theGimp]

The Cuban regime is despicable, but I don't see what they have to gain by targeting diplomats -- particularly US diplomats.

I'm inclined to believe the theory that the damage is inadvertent.

[devrandomguy]

Perhaps it was not government sponsored, but rather an attack by one or more local extremists, of some sort.

[riskable]

Guerrilla radio? Not rebels, decibels.

[andrewpi]

Often diplomats are spies that operate in a country under diplomatic cover; perhaps Cuba wanted to frustrate suspected spying?

[mythrwy]

Perhaps a third party not wanting to see better US/Cuba relations?