date: unclosed date string comments

[sunnycemetery]

Hello.  Given this documentation:

Comments may be introduced between round parentheses, as long as included parentheses are properly nested.

Is this considered a bug:

■ LC_ALL=C date -d '(test 1 2 3'
Wed Aug 5 00:00:00 EDT 2020
■ LC_ALL=C date -d '((test 1 2 3)'
Wed Aug 5 00:00:00 EDT 2020

Thank you.