“was Laundrie setting up an alibi?”
/bingo
Ted Kennedy did the same thing when he went to the he went to the hotel front desk and asked for the time.
According to these accounts, he likely did the deed (outside the van?) then walked to a shower station to wash away and dump obvious evidence (and possibly the body en route) then tried to hitch from there. In doing so, he may have been thinking to establish an alibi and took particular care to mention his fiance in present/living tense in both of those short trips. He curiously reversed direction, was adamant about avoiding Jackson or the scene and skittish/freakish in both cases (particularly driver #2 saying he didn’t want her to take him to his campsite because of his fiance - if only shd knew how dead on she was).