There are several antonyms for the phrase "had a look-see." These include phrases like "ignored completely," "blind to," and "overlooked entirely." Additionally, instead of simply having a cursory glance, one might opt to "scrutinize intently" or "examine closely." Conversely, if someone is simply taking a quick glance, they might be said to be "glancing momentarily" or "taking a passing peek." Ultimately, the antonyms for "had a look-see" are varied and dependent on the specific situation and degree of attention paid to the object or situation being observed.