If a raccoon is involved, more likely than not it is catching chickens in the dark. Therefore they are likely on the roost when first encountered. To protect from raccoons, the coop / run needs some looking into to block raccoon access.
It is easy to go years between losses of chickens to predators, with or without roosters. It is also easy to go years with frequent losses to predators, with or without roosters. There can be a random nature to depredation which is why we hear such varied accounts on keeping chickens...