re: Investigators When they KNEW Murdaugh lied (Page 112)

I’ll bet he had the rifle on a sling in front and just dropped the shotgun to draw down on Maggs.

Probably a combination of things, there were so many details to cover and he did, almost, 1) not knowing about Paul’s Snapchat he thought his timeline and alibi was solid and wasn’t as careful, 2) maybe not as knowledgeable about the extent of info that can be obtained from phone data.
But probably mostly #1.
The two family guns thing is bizarre but I guess to support it being local rabble mad about the boat wreck. Maybe afraid of trying to get outside guns? Outside guns would have been much better IMO.