Tiepoint grid shapefile number of items?

Hi! In below screenshot, one can identify 3 different amount of features (the COUNTS row of the dataframe, the "Feature count" item in the QGIS UI), for the same local coreg activity, the first 2 in the Jupyter notebook I understand, it's the difference between outliers excluded (= the gcps table) or not (the crltab table). But why does the tie-point grid shapefile, created with CRL.tiepoint_grid.to_PointShapefile() have another third value for the number of features? And how could I only have the valid, no outlier included points as a shapefile?

Thanks!