How Did Gabe's Death Be Suspect?

Gabe was married only 11 days to tina. When detective garinger and i were assigned to the investigation, i could not see how tina's death would be suspicious. As far as suspicion was concerned, i myself am not a diver. Whilst i thought it was unusual for him to leave his wife of 11 days, people do strange things when they're panicked. Police would eventually question every person from both boats. Not everyone was questioned face to ace, and not everyone was questioned straightway. But everyone involved in the actual incident was interviewed at some stage by police.