The clue in these sentences suggests that the most relevant option is:
Max was in the same serious accident that killed Sam.
This is implied by the mention of Sam's bruises and cast, which indicate he sustained injuries during the accident, while Max, who notices these details, did not have any injuries. This hints at a potential twist regarding Max's own fate and relationship to the accident, leading the reader to consider whether he is alive or has a different connection to Sam's death.