Gale might have died up to a dozen times by the time you reach act 3. Especially with Withers, dieing is no big deal for you, so neither would blowing up be for Gale.
And even if you want to ignore Withers, its explicitly shown that Gale owns a True Ressurection scroll, so coming back to live after the explosion is possible.
Just another failure of Larians storytelling.
