As much as it is current to blame terrorism on everything, I don't believe this is the explanation here for one reason: where is the claim of responsibility? Not much point in committing an act of terror (after all, you do so fro a political aim) if nobody knows you did it.
Presumably using the same reliable logic, Lockerbie could not have been a terrorist attack as no responsibility was claimed in the first 24 hours, correction, 24 years.