Quick release hubs have hollow axles that flex slightly when the quick release is closed. Hub bearing adjustments must account for this extra pressure. When a quick release hub is not clamped tight in the frame, there should be a slight amount of play in the axle. This play disappears when the hub and wheel are clamped in the frame.
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If the axle has play when the wheel is outside the bike, but no play inside the bike, the adjustment is adequate. If there is no play in the axle when the wheel is outside the bike, the adjustment is too tight, even if the axle seems to turn smoothly when out of the bike.