Personally i don't think either IHH or IDF are credible on this. Some of the IHH were obviously ready for a fight, though clearly they weren't terrorists and were only equipped for a minor riot, not a full scale gun battle. Equally, the IDF clearly did not set out to kill people. However, frankly the approach they took was one of the most incompetent displays of military idiocy I have ever seen. You wouldn't dangle people equipped with paintball guns inside a house where you were trying to evict people, let alone over a ship that Bibi had for weeks ben saying was full of terrorist sympathisers. The toll of dead and wounded aid activists is completely appalling and completely due to the sheer incompetence of the operation and panicing commandos who should never have been put in the situation they were. The IDF and Israeli government's message that none of their people did anything wrong is laughable.
Israeli troops shoot, injure Palestinian crossing Gaza border fence (Haaretz)