Unexceptionable
/ˌʌnɪkˈsepʃənəbl/
Definition 1 of 1
Pro Tip 1/3Beyond Reproach
Use 'unexceptionable' to describe something flawless that cannot be criticized. 
The research methodology was unexceptionable and widely accepted.
Pro Tip 2/3Positive Connotation
'Unexceptionable' carries a positive tone, implying something is beyond disapproval. 
Her thesis defense was unexceptionable; the committee praised her work.
Pro Tip 3/3Formal Contexts
The term is more common in formal writing than in everyday conversation. 
In an official report, the officer's conduct was deemed unexceptionable.