it appeared to be a typo, and as you suggest the compiler caught it

    var foo *Foo
    var err error
    if foo, err = getFoo(); err != nil {
        return nil, err
    } 
    //foo is usable now

That solves nothing. The point was that you pollute the scope with error variables, leading to dangerous logic errors that can be hard to spot. Your snippet is no better than:

  foo, err := getFoo()
  if err != nil {
    return nil, err
  }

"err" still ends up in the scope.