One thing about "intent" in criminal trial is that it is ALWAYS something that is inferred, because it goes to what the perp was thinking, and no one can truly know what someone else was thinking at the time. Even if the perp himself testifies as to such-and-such a mindset, you still can't know that this was what he was really thinking at the time of the crime. So the idea that it has to be inferred here, by what else is seen, is no different than any other case.
Also, intent/premeditation do not require a long meditation that preceded the action. It's just separating the difference between whether the jury says it happened on purpose, or didn't.
But nothing so far supports something accidental, and imo the argument can be made - and will be - that "intent" was shown by EA's subsequent actions (his lying, his coverups, his continued and ongoing attempts to keep anyone from knowing what happened to CM, and so on). If it was an accident, you say it early and often and do what you can to mitigate the effect of your actions, and still to this day EA has never done one thing to lessen the damage from his act of abducting CM.