I think I've seen the following argument somewhere, but I can't remember where:

Consider the following villainous arrangement: you are locked in a watertight room, 6 feet high. At 8 o'clock, a computer flips a quantum coin. If it comes up heads, the computer opens a valve, causing water to flow into the room. The water level rises at a rate of 1 foot per minute, so by 8:06 the room is completely flooded with water and you drown and die before 8:15. In either case, the room unlocks automatically by 8:15, so if the coin landed tails you may walk out and continue with your life.

At 7:59, you assign a 50-50 probability that at 8:03, you will experience being up to your waist in water. If you believe in quantum immortality, you will also be assigning a 100 percent chance that at 8:15, you will experience being completely dry and walking out of the room in perfect safety. Since every world-line in which you're in the water at 8:03 is also a world-line in which you're dead at 8:15, these probabilities seem inconsistent.

This suggests that you should consider a 50-50 chance of having your subjective experience snuffed out, since you could find yourself in the water-rising world, and there's nowhere to go from there but death. The other possibility - that you'd be shunted for some reason into a valve-doesn't-open branch even before there's any threat of death - seems to require a little too much advance planning.

But no form of death is instantaneous. Even playing quantum Russian Roulette, there's still a split second between the bullet firing and your death, which is more than enough time to shunt you into a certain world-line.

This doesn't go so well with the adorable zombie-face graphics above. It would go a little better with a model in which, at any point, one copy of you was randomly selected to be the one you're experiencing, but that model has the slight disadvantage of making no sense. it would also go well with a model in which you can just plain die.