Islander, his healers were behind him. BEHIND. If he'd passed to Mallo instead of interceding to him at the beginning, Mallo would've been violated and poked with sharp pointy objects by the respawn in short order. The healers could not have reached Mallo in time to save him.
By the time he (edit to clarify: Myrmio) gets out of his first stunlock, Mallo was swarmed by the spawn so an interception would've been very likely.
He arguably could've passed to Sabina (full health) at one point, but Sabina dropped down so that pass would've been incomplete. Mallo was at half health with a bunch of enemy leapers in the pit waiting to jump to him had Myrmio passed to him.
Did I mention that I was in vent with him at the time so he KNEW I would be coming into the pit to keep him up?
But hey, let's not let this interfere with Islander's Monday morning quarterbacking. Monday morning quarterbacking is FUN!