英语提问：麻烦各位帮我分析以下句子的成分,搞不清楚了.

英语提问：麻烦各位帮我分析以下句子的成分,搞不清楚了.The inspector suggested that he was lying because,that morning,the 8 o'clock train broke down,so the man must have caught the 8.25.最主要是so后面这句话不知做何解.because,that morning,the 8 o'clock train broke down .是状语从句；The inspector suggested that he was lying.是主句；so the man must have caught the 8.25.这句话又是个什么东东呢.关键是so又不是连接词,因为because与so不能出现在同一个句子中,so 只能做副词.但是副词不能连接两个分句,请学英语的朋友帮忙解答.