IMO, many YouTubers and podcasters can make a mess out of a case, get on the bad side of LE, but not Chris Lambert. I'm listening to the podcast series again (Your Own Backyard) and he is very well researched, does not repeat everything he hears, fact checks, re-checks sources and is very calm and methodical when he talks about the case.
It appears that people that knew Paul Flores in High School, college, after college, or saw him and Kristen that night were comfortable talking to him, many saying no at first, but then changing their minds after episodes of the podcast were released. Kristen's parents, after pretty much saying no to interviews over the years (they thought hosts/shows were self serving in talking about their daughter) trusted him and took part. He got praises from a active LE investigator on the case who even agreed to an interview on the podcast. I personally give him a huge thumbs up for his style and for being respectful. IMO