ArcGIS 10.2 Spatial Join with "are identical to"

I use Spatial Join with "are identical to" to convert ID attribute from one join line layer to target line layer. The XY Tolerance is default.
The problem is:
two lines in join layer have different ID values with the same start and end point but little different path;
resulting in target layer with the same ID value (one of the join layer ID repeated).

Is this a bug?

Anyone has any solution?

Thanks.