by brady:

In the csv.NewReader() call the input should be checked to see if it already is a
bufio.Reader and if so it should be used directly rather than creating a new buffered
reader. This would allow a reader to continue in the stream where a previous reader
might have failed.

In this example [ http://play.golang.org/p/j7B5yzdsdC ] It would be nice if we could get
the remaining file after the read call failed but it is completely consumed by the
reader.

This would require the following change on this line (or whatever more readable version
of this you prefer).
http://golang.org/src/pkg/encoding/csv/reader.go?s=3686:3721#L106

// NewReader returns a new Reader that reads from r.
func NewReader(r io.Reader) *Reader {
    if bufr, ok := r.(*bufio.Reader); ok {
        return &Reader{
            Comma: ',',
            r: bufr,
        }
    }
    return &Reader{
            Comma: ',',
            r:     bufio.NewReader(r),
    }
 }