Assuming for a minute that KC applied the duct tape to an alive Caylee, what evidence shows that she could not have been in a rage both when applying it and for several minutes afterwards, until it was too late?
KC didn't wake up in a rage. At 7:56 a.m. she is instant messaging witeplayboi. You can see where KC's mind is. She's hardly in a rage.
Snipped...
WitePlayboi (8:01:33 AM): so what r u up 2
casey o marie (8:02:02 AM): not a whole lot. checking up on all the myspace/facebook hoopla
Snipped...
casey o marie (8:05:40 AM): casey really likes this boyfriend of hers

Throughout the day KC downloads a picture of Fusian to her photobucket. She leaves messages on social sites. She texts. She talks on the phone.
KC managed to ping, meet up with witnesses and leave a computer trail pinpointing HER locations for every single one of the 31 days she was "hiding out" except for June 30 into the morning of July 1.
Cindy was in the house when Caylee was put to bed ALIVE June 15. George was in the house until 2:30 p.m. June 16. No intruders were IN the Anthony house ANY of June 15 or until AFTER 2:30 p.m. June 16. By 3 p.m. June 16 KC is back ON AN ANTHONY COMPUTER. Cindy, George and KC are the only ones with access to Caylee after Caylee got home from Shirley's house until 1 p.m. June 16. That gives another person outside of KC from 1 p.m. until 3 p.m. IF KC left her paren't house. But whatever happened to CAylee still had to have happened while KC is close enough to ping in Anthony house locale. (Which excludes Blanchard Park & Sawgrass Apts.)
Sometime before KC met up with Tony on June 16--her pings put her at his apartment by 4:30 p.m.--something happened to Caylee.
How many minutes did KC have off of her cell phone to deal with crazy intruder kidnappers? Or to try to revive her baby from a surprise accident? That is before she was on the phone again...how'd she manage to get calm enough to make plans with Tony,lie to her parents and say she was going to Tampa, discuss Fusian's upcoming Friday night event with friends on facebook within mere minutes after her child catastrophically was kidnapped or accidentally died? IMO, she had to hustle and be deliberate to purposefully do the deed herself and be out of her parent's house before Cindy got home.
KC stupidly(IMO) managed to get herself videotaped on June 16.
Jurors are allowed to and do take a defendant's demeanor into account when deliberating. The instructions say a defendants behavior matters.