You keep making that "deliberately lethal" charge, but no one else with any credibility is making that claim on either side. The intelligence agents, which is a bit of a misnomer in this case, had a plan -- two bombs. The first went off to force the crew to evacuate the ship, which they did. The second was intended to sink the ship, which it did. However, the agents did not anticipate people re-boarding the ship between the two bombings. It was inadvisable and bungled.
You can say that they INTENDED for people to reboard the ship between the small and larger bombs, but it makes no sense, and the French had nothing to gain. It didn't send a message, it was an enormous public embarrassment and very costly politically. And if they intended to kill all those people, then why a smaller bomb and then a larger one later? Just the larger one would have sufficed, and had a much better chance of actually killing people.