Control is wider than a motionless hold
Under Law 12, a goalkeeper’s hand control includes bouncing the ball or tossing it in the air. More than eight seconds of that control inside the penalty area leads to a corner. The referee determines the start and shows the last five seconds.
Suppose a keeper catches a cross, holds it briefly, bounces it twice and catches it again. Treating each catch as a fresh possession would artificially divide one control period into several. The ball moving away from the gloves during a bounce does not by itself create a reset.
Match your observation to the official count
The broadcast clock may be too coarse to establish exactly when control began. A keeper can also gain control before standing upright, so timing only from the moment they rise can omit part of the sequence. Watch the referee’s arm alongside the keeper’s actions.
This explains the corner without assuming the ball crossed a goal line. It also helps distinguish the possession limit from a separate offence involving an opponent preventing release. On a replay, first ask whether the keeper still had the form of control described by the law. Then inspect the official’s countdown and resulting restart. Avoid adding a private extra allowance for every bounce simply because the ball briefly becomes airborne.
Questions answered
Does a bounce start a new eight seconds?
No; bouncing is included in hand control.
Must the ball leave the field for this corner?
No. The corner can be the sanction for exceeding the control limit.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.