He may have been very close to the end of it or off of it by that time. We just know from the released documents that he cycles the round (as heard in the video's audio track), one of the girls states that he has a gun and that he tells them down the hill. So definitely in the immediate vicinity of the bridge. I suspect that if we could see the video, we'd actually know the answer to your question though; the trial will tell no doubt.
I also note with the blue highlight that that LE states in this document, "
the cycled ‘round matching that firearm was located within feet of Victim 2’s body." They do not call it a "misfired round" that was found within 2 feet of their bodies. Those with experience can tell the difference between a round that's merely 'cycled' and one that is actually 'misfired' as a misfired round would have additional markings from the firing pin etc. I think their specific choice of wording here actually tells us that the round was a "cycled round" and not a "misfired round" - they had years to have it analyzed by the pros prior to writing this document.
I also note that if it is identified that it is actually a misfired round at trial, , and I highly doubt it will be, ... that any good defence attorney worth their salt at a death penalty trial will be utilizing the above text where they've identified it as a "cycled round" as grounds to undermine the credibility of the prosecution ballistic expert. They are not the same things; they are different beasts altogether.
Edited to add link again (Page 6, para 3):
