For the most part maintaining a safe following distance, and not driving too fast for conditions will prevent 99.9% of such incidents, but I do agree that in the rare occasions when reactions times are at a premium such as a branch falling on the road right in front of you, or an animal darting out of some bushes, indicators should be less of a priority than braking/evading. Violently swerving is almost always a bad idea without shedding as much speed as you can first, though, and even then it's probably better to just hit the object, unless it's a child, rather than risk a roll-over.

That's not what you said though. You said 'something the car before you swerved around'.

Edit: Yeah, your downvote just tells me you're a shit driver.