The lower left flap is not quite touching the side panel, in two places, so the point trim does not work there, without modification.

The intersect "script" is the same as the construct/curve/isect command, (I think.)?

EDIT: Run the script "MarkOpenCurveStart" to see several spots where the lines do not quite intersect.
Need to zoom in a lot to see them. Might cause problems in other programs operation?

I guess some of them are within some tolerance value?