Why the kyberdart? Why not a blaster?
Why would Jango use the kyberdart to kill Zam and allow Obi-Wan to trace it back to Kamino, thereby discovering the massive cloning project underway there?
If all this was somehow part of Darth Sidious' plans, then why would he then try to have Obi-Wan killed in order to prevent him from discovering the cloning facilities when he arrives on Kamino? If Darth Sidious wanted the cloning facilities kept secret, then it doesn't make sense that Sidious would lead Obi-Wan to Kamino.