Was getting captured also a part of Evans plan?

YES , as Evans knew that someone would crack the plan and would find him in the Golden Lion. So he had arranged a fake police van and constables. So that when he is caught , he would go with them and would have the final escape without giving any suspicion to the General. It is said that the General got call during the exam time about the van and the constables to take Evans after the exam , which was a part of their plan