A poor fielder may "avoid" many errors simply by being unable to reach many balls that a better fielder can successfully reach, possibly creating a situation where the poor fielder will have fewer errors than an otherwise better fielder.
A poor fielder may "avoid" many errors simply by being unable to reach batted or thrown balls that a better fielder could successfully reach. Thus, it is possible that a poor fielder will have fewer errors than an otherwise better fielder.