i DON'T think you should back out, because the title insurance will get you back that piece of land: they will demolish the existing fence, and will built a new one on the right location, out of their pocket, and your future neighbor will be compensated for the loss of that land strip. Just make sure that you have the seller bought the title insurance for the final close. Our neighbor won back their lost piece of land strip, without paying out a single dime to anyone, in the same situation as you are in but after the sale.
As a side comment, you should not confront your future neighbor yourselve.
您们有遇到过这事吗？如何处理呀？
我的理解是fence不一定建在边界线上，我自住房有同样问题，另外邻居有可能也做一个Survey,还不好说
我家住好区，刚搬进去时白人医生邻居还想占便宜呢，把拉场筒放在我家车道上，还说By law 可以的。被我巧妙化解，现在相处得很好
另一边白人邻居没有Fence,整天想占点便宜，今年终于把栅栏做上了，没做Survey,差不多就行了，后边那家还占着呢，也算了
如果没过期，你可以退出同时拿回来定金
如果过期了，那就是你自己和你中介的的失误，中介有义务提醒你到期日，如果没提醒你，你可以告中介
建筑商造的新房子，亲戚搬入后，邻居要求和他同建篱笆在界线并分享费用。
亲戚（单身）不在乎没同意，于是邻居自己很不高兴地请人造了。亲戚那时没注意篱笆是否是在邻居自己那边（边界上原来的survey铁纤已不在）。
其后邻居和市里告状几次说亲戚不割草影响市容。过了两年他们卖房搬家了。换了新邻居。
又过了两年，亲戚想养狗，于是给新邻居发邮件问是否可以连接自己的篱笆到他们的篱笆。没想到新邻居非常不友好，不但说不行，还威胁要去找律师。
亲戚觉得莫名其妙，来问我们怎么办。我们觉得可能是上一个邻居给新邻居洗过脑子。避免冲突最好方法是请survey公司重新survey放上边界铁纤后再做篱笆。
结果survey发现那条篱笆不仅占了亲戚地盘若干英尺，还占了市里的地（房子两边靠马路）。亲戚把survey结果发给新邻居，他们马上软了道歉，并同意放入铁纤表明边界，但求亲戚不要让他们重建篱笆，亲戚心软同意了。然后不久这个新邻居也卖房搬走了。后来亲戚也卖房搬到其他城市去了。但那份survey是卖房合同的一个附件。
老公每次去都和邻居聊聊，同时告知只租给好人，我们这种老实人也做不大到是
i DON'T think you should back out, because the title insurance will get you back that piece of land: they will demolish the existing fence, and will built a new one on the right location, out of their pocket, and your future neighbor will be compensated for the loss of that land strip. Just make sure that you have the seller bought the title insurance for the final close. Our neighbor won back their lost piece of land strip, without paying out a single dime to anyone, in the same situation as you are in but after the sale.
As a side comment, you should not confront your future neighbor yourselve.