Let's look at this another way:
Something happened Sunday night. Blunt force or stabbing injury....
TS finds herself with a decision to make. Clearly she chooses HERSELF.
JMO it seems likely she would've medicated him at this point. Not to treat an injury, not to provide him comfort, but to keep him immobilized and quiet while she tried to figure out her next worst decision.
I have to wonder if she'd hoped to overdose him.
I have to wonder why she didn't leave with Gannon during the night.... girls asleep. Gannon, injured, drugged, dying, she could've done everything she did by day under the cover of night....
Which makes me think she expected him to expire overnight....
I have to believe her options were restricted by the population in her house.
She had to be working out a story to fit a rapidly changing set of details...
Could she have plotted/concocted the runaway story overnight? But why? The girls likely saw him last Sunday night... so if she disposed of him overnight, she could have stuck to her He Left To Go To A Friend's House / He Ran Away / He Left With Someone at 3:15pm story....
This leads me to wonder conversely if, at least the night before, she wasn't premeditating murder. Could she have spent the night cleaning up and repairing evidence of ABUSE while expecting him to recover? Drywall repair, banister repair, flooring repair, etc? At this point, maybe she wasn't covering up for eventual murder but for abuse??????
Because why didn't she remove/murder him overnight?????
Whyyyyyy wait until broad daylight?
My head hurts.
JMO
My theory is the same as yours. Gannon did something by accident to cause LS to:
"I just flipped out, okay?" (It's
your fault, Gannon.) By that statement she was trying to justify to Gannon what she had done to him and I think it was a reactionary "sharp object from the tool supply in the garage-attack." She may have already had the tool in her hand if she was cleaning up the tools in garage already. Gannon was bleeding and frightened (he didn't cut his foot at all, imo) ...and she "medicated him" to calm him down and, literally, to knock him out. The other 2 kids in the house would have heard Gannon suffering all night long otherwise. She had to quiet him down so it would appear to the other 2 kids that he was okay and not seriously injured.
This would also explain Gannon becoming incontinent and having an accident some time during Sunday night--early Monday morning. I don't believe LS's statement that Gannon's own medication caused the "incontinence problem" on a fairly regular basis at all. I believe it was the pain medication causing him to be unable to react quickly to get to the bathroom or not waking at all to use the bathroom, and being fearful about his situation that caused the incontinence problem. In spite of bandaging Gannon's wound, he may have bled on and off all night long. Puncture wounds can bleed out
and internally.
LS was awake all night long on Sunday, imo... taking turns quieting Gannon down if he woke up in pain in spite of being drugged, observing him for changes in condition, cleaning up the blood... cleaning up the evidence of his incontinence, doing a laundry that resulted from that, repairing whatever "unforgivable and flip-out-over" damage Gannon had done by accident on Sunday, and gathering items to put into the truck (suitcase, 2 x 4, gun, etc.)
Pain and still being under the influence of the pain medication could explain how Gannon walked out to the truck on Monday morning. Perhaps she even medicated him again that morning while telling him she was going to take him to the ER. He would then have, hopefully, been sound asleep when arriving at his place of execution.
While she worked, she planned and plotted out his murder that she had decided would take place at her earliest opportunity on Monday morning. That way, she'd have time to get home and continue cleaning and checking for any remaining suspicious signs that would indicate that something very terrible had happened on Sunday night.
Megnut, I think she didn't dare take Gannon out to kill him during the night hours between Sunday night and Monday morning because the other 2 kids might be wake up and LS would have no explanation of why she was heading out with Gannon at a time like that. I also think she wanted the house to look somewhat "put back together" and "normal" by the time they woke on Monday morning. That's one reason she drugged Gannon, imo... so they would think he'd had a little accident but, oh good!.... he's fine now and sleeping soundly. Maybe HH was out of the house when the Sunday incident took place so she would have been none the wiser if Gannon was in bed sleeping when she got home.