Line wrapping issue with trailing space

[MikeTO]

The three lines of text in this test document are almost identical

1. Has a trailing space with auto kerning of -70 between the period/space
2. Does not have a trailing space
3. Has a trailing space without kerning

Kerning only moves the second character (the space) to the left and has no effect on the position of the period. So why does the period fit with a kerned space (1) but not without a space (2) or un-kerned space (3)?

test.afpub

[Lee D]

Thanks @MikeTO I've logged this with the developers.