Over del. tolerance Unlimited-Tick in SA

Hello All,

In SA item level initially the over del. Tol. is unlimited ticked, i received the ASN more than sch. qty and posted the GR successfully.

Now i unchecked the unlimited of the line item and trying to post ASN qty more than the Sch. qty. it is posted successfully and inbound del. created

Question is why it is not giving me any error after removing unlimited check ? this is the standard behaviour of SAP ?

Error msg ME-161 is in Error mode

Thanks