Well, I'll be. Here's something interesting, interesting to me at least.
Here's the website that has the video and transcript. The headline says it's the "full interview."
ABC Exclusive: Full interview with Brian Laundrie's sister on Gabby Petito
You have to scroll down to the second video for the interview. The transcript is further down and contains all of the questions that the producer asked along with all of the responses.
The video was edited to remove questions about the van. The whole interview tracks word for word except for that in some cases, the questions were just cut out AND there is also a whole section that was cut out at around the 2:55 mark, and skips right to her assessment of how he behaved in the body cam video (maybe at the request of LE?).
Everything italicized is cut:
Question: Did the police say anything else about...?
Cassie Laundrie: No, I only had their initial questions and I haven't been contacted again and, and whenever they want to contact me again I'm here waiting they have my number.
Question: Did you know that the van was back and you're...?
Cassie Laundrie: No.
Question: So you didn't know that he came back without the...?
Cassie Laundrie: I assumed he flew back, because that's what he did when he is - actually I don't want to say that.
Questioner: No problem. No problem.
Cassie Laundrie: I think that's more police stuff.
Question: Okay, um, but is it is it like out of his behavior to go on a trip with her and then just leave her somewhere like has anything like this ever...?
Cassie Laundrie: No, I mean. No, nothing like this has ever happened before.
Question: But I'm saying he doesn't really have. Does he have like the personality to where he would?
The video picks up after the cut with her answer to the last question: "No, he's very um... He's very. He always does the right thing, like in the body cam he's - he cooperates with the police, and he - he's is a wonderful uncle. He's always been there when I need him. He's, I mean, he's been there every time Gabby needed him."
His sister heard he was home, and assumed he had flown and left Gabby with the van. So the allusion to thinking he flew was about how she thought he got to Long Island when he returned home after Gabby went missing. It isn't about the trip from Utah to "clean out the shed."
Interesting that even his sister wasn't told that he drove home.