When Ryder confronts in him for an explanation and apology, the angara reveals the nature of the Vesaal, a lottery system that chooses who gets to live on Aya for a short time. When the Initiative's diplomats came to Aya, it disrupted the system, so in order to make room for the new arrivals, several angara had to sell their slots. Jarryn's friend sold his slot in exchange for resources for his family on Havarl. In the end his comrade was killed by the kett on Voeld.
Though Jarryn was angry for Lenn's part in his friend death, he was remorseful for his anger. In addition as he respects Lenn as he didn't show any fear towards Jarryn when he approached him.