I'm not only wondering who they were but when did they come forward and claim they saw her? Also, when did they see her - it's not an alibi if they saw her at 9 pm at night and at 6 am in the morning.
How is it possible she was not caught on camera?
So, it makes me wonder if Nina was one of the witnesses or whoever they were, but there was other conflicting information? Like Nina was a witness but someone was seen on the porch so that didn't work out. Or Nina's phone was not at the hospital when she said she was at the hospital. Just hypotheticals... it could be someone besides Nina.
Why are you assuming Dina isn't on camera footage? Gore never said he looked but couldn't find her. Of course she wouldn't be on the video if he never looked for her to begin with. If he had witnesses and also cell phone triangulation, he didn't need to spend additional resources to wade through security videos at all.
The explanations of witnesses and cell phone records seems to have satisfied both Ms. Rule and the Sheriff.
JMO