Both in general, and/or in your specific example, I think downvoting should always be part of the solution to incorrect answers.
I do not think incorrect answers are useful so when I see them I always downvote them. This helps reduce their answer order ranking, and if they are pushed into the range of moderators or trusted users with the delete privilege, then they may be removed from the site. Although moderators can delete any answer we rarely do that unless they’re into negative territory.