Of course it was a bomb, just like the downing of the Russian craft in Egypt was a bomb. Whatever a country needs to be a bomb, is a bomb. I look back on the 1960-2000 period and I just have to say, what a waste. So many mechanical or structural failures that could have been classified as bombs but were not. What on earth were security agencies thinking at that time?! Never let a crisis go to waste. It's a gosh darn good thing that we have learned that lesson so we can find a terrorist wherever and whenever we need to give the public a good scare and keep them in line.
It's a bomb citizen, do your duty and be frightened. Nothing else to see here, move along.