How does Facebreaker/Zhonya's Hourglass interact with Vilemaw's Lair when the attacker is stunned?

Ruling: When both the attacker and defender are stunned, the attacker will be recalled back to base because there are still defenders present. Recalls are not considered moves.

Sequence:

• Both units become stunned
• The attacker (Lee Sin) gets recalled to base
• This occurs because defenders are still present

Nuances:

• The recall happens even though the unit is stunned because recalls are not moves