Test Case expecting no diff to be found

[gtnarg]

Curious why the expectation is that there should be no difference detected in the following test case?

Old text: By virtue of an agreement between xxx and the <b>yyy schools</b>, ...
New text: By virtue of an agreement between xxx and the <b>yyy</b> schools, ...

Expected diff: By virtue of an agreement between xxx and the <b>yyy</b> schools, ...

Thanks, Grant