Spoofchecker yields false positives by defaut when Whole-Script Confusables (WSC) and Mixed-Script Confusables (MSC) checks are used.
They have been deprecated since ICU 58:
http://bugs.icu-project.org/trac/ticket/12549#comment:10
Workarounds: upgrade ICU to 58+, or avoid the MSC and WSC checks with Spoofcheckers' setChecks() function.