A verdict has to be unanimous, so yes one person can prevent a guilty or not guilty verdict in any case. If the holdout can't be brought around then you have a hung jury.
The prosecution can retry a defendant in the event of a hung jury. However in this case it's possible the judge might grant the defense's motion for mistrial in the event of a hung jury which would mean that Kyle would walk on everything.
So basically, if there's a juror that is adamantly saying Kyle is guilty, they may in effect make it so that that he can walk free anyway.