The Supreme Personality of Godhead will certainly protect a devotee who does something sinful accidentally. As the Lord says in Bhagavad-gita (9.30-31):

"Even if one commits the most abominable actions, if he is engaged in devotional service, he is to be considered saintly because he is properly situated. He quickly becomes righteous and attains lasting peace. O son of Kunti, declare it boldly that My devotee never perishes." However, if a devotee or so-called devotee purposefully commits sinful activities continually in the hope that Krsna will give him protection, Krsna will not protect him. Therefore Sri Caitanya Mahaprabhu said, kali ke rakhibe, yadi na dibe raja-dhana?: "Jagannatha has saved Gopinatha Pattanayaka from being killed by the King today, but if he commits the same offense again, who will give him protection?" Sri Caitanya Mahaprabhu thus warns all such foolish devotees that Jagannatha will not protect them if they continue to commit offenses.