Imâm Sâlih bin Fawzân al-Fawzân
Question: If the imâm is prolonging the prayer and a person led by him is busy and has a need that cannot be done later, is it prescribed for him to separate from the imâm and complete the prayer by himself?
Answer: Yes. If he for example needs to separate from the imâm because otherwise he may lose property, he can change the intention and separate from the imâm, complete the prayer by himself and leave.