[Pitchwife]

Or, in more words: the only way Maedhros could construably be blamed for Lalaith's death would be if by better timing his attacks he could have defeated Morgoth in time to prevent the ill wind and the plague being sent. But as Mandos made clear when the Noldor left Valinor, they never had a hope of overcoming Morgoth without the help of the Valar, no matter how great their prowess and courage and how cunning their strategies might be. So if anybody else than Morgoth is to blame, it would be the Valar for setting him free in the first place, and for taking so long to come to the help of the Eldar and Edain after his return to Middle-earth.

EDIT: x-ed with the phantom.