Three comments to address your question specifically:
1. Note the "more often" in the definition. It isn't "always". As such, sometimes introverts are energized by their social time.
2. Given the spectrum of extroversion and introversion, some folks may be less extreme and therefore exhibit less stereotypical behavior for their archetype.
3. Extreme introversion (or extroversion) is not perceived as being pathological until it "causes impairment in functioning and/or causes significant distress for the individual" [ibid]. This might be in the form of detachment that has some surface level similarities to being an extreme introvert, but is actually quite different.