The strings broke at an inopportune time for Sindhu, the sideways drift caused a problem, she was wrongfully disallowed the 2nd challenge (she was quite fast then).
Other than these, this was an encouraging display from Sindhu. Tai isn't invincible anymore, it showed. Sindhu could stay toe-to-toe with her until Tai lifted her game in the very big points.
All this bodes well for the upcoming Dubai World Superseries Finals.