Can an Assessing Officer examine all matters when a case is selected for scrutiny through CASS?

Recently an issue appeared as to whether an A.O. has any scope to examine all matters when a case is picked up for scrutiny through CASS or based on information obtained through Annual Information Return.
A general view says that the A.O. has restricted scope of to apply his mind when a case is not picked up for scrutiny as per section 143(2) (ii) of the Act.
The selection through CASS on the basis of AIR is done through a mechanical process in which the A.O. has very little scope of enquiry in connection with verifying the information found in AIR relating to the assessee.
The Central Board of Direct Taxes (CBDT) vide instruction no. 7/2014 dated 26.09.2014 has passed a direction that in case of the cases selected for scrutiny during the Financial Year 2014-2015 through CASS based on AIR, the scope of enquiry should be restricted to verification of the particular issues only. In such cases, an AO shall confine the subsequent enquiry only to the specific issues on the basis of which the return has been picked up for scrutiny.

Kinds of Selection of cases for Scrutiny:

There are two types of selection of cases for scrutiny:
1. Computer Assisted Selection of cases (CASS); and
2. Manual Selection of cases for Scrutiny.
The Compulsory Computer Assisted Selection of cases for Scrutiny (CASS) is currently done under two categories:
(a) Compulsory selection – Under this category, cases fulfilling some particular criteria are selected which are generally derived from the Central Action Plan of the Department. The system emphasizes on quality selection of cases rather than selecting a large number of cases.
(b) Score based selection – Under the score based selection, a case is selected based on some pre-defined criteria with high risk potential.
Cases for scrutiny are selected manually on the basis of directions given by CBDT each year. Apart from compulsory manual selection of cases, an AO may select any case after recording reasons and obtaining approval of his higher official. Cases not selected under CASS are observed by CCIT regarding the quality of their assessment.

An assesee can ask for restricting scope of enquiry of the AO:

If the notice for scrutiny is issued mechanically on the basis of only AIR and without any other reason recorded by the A.O., an assessee can as a matter of right request the A.O. to restrict his scope of enquiry relating to issues covered by AIR.
The assessee should have copy of order sheet and other documents to prove that notice has been issued only based on AIR and as per necessity observed by the A.O. after applying his mind. The issue might involve litigation and further considerations.