Ec not matching with mother document

I am going to buy a land. Actually I got EC from 1980. My bank’s legal team is saying that the land was registered uyil at 1998 and that information is not available in EC. The EC reflects 2005 registration and 2008 registration as per sale deed. The mother document reflects the uyil at 1998 and the same is not reflecting in EC. I planned to buy through bank loan, so that I didn’t go for separate legal opinion. This particular land owner was brought through Bank loan only, that bank didn’t noticed or this is missed by them also? Remaining all title deeds are matching with EC till date except the 1980 registration. The legal team is saying that it is the mistake by registar office but there is no problem in deeds. How much I believe this? Someone please help me whether it is a clerical mistake or Uyil will not reflect in EC?