I saw Janson yesterday.We haven’t seen each other since we l

I saw Janson yesterday.We haven't seen each other since we left Beijing.这句话用现在完成时对吗?
为什么这句话却用过去完成时I saw Li Lei yesterday.We hadn't seen each other since I left Beijing.

I saw Li Lei yesterday.We hadn't seen each other since I left Beijing.
这句话没错啊.昨天已经见到了,所以没见过的状态只维持到昨天,所以要用hadn't.
再问： 后面还有一句呢？您帮忙看看分析分析。
再答： 。。。 我说的是后面那句没错。 你标题里那句是错的，haven't 应该改成hadn't，理由同上。