DATAPUMP impdp: dump file contains more columns than target table but no failure.

Not sure if this is the indended way datapump works. I have a table exported with expdp with 8 columns and by chance i loaded this data into a target table with 7 columns.

Database version is 11.2.0.3

OS are linux RH and solaris

Here is the syntax i used

SQL> desc USER_A.TAB_A
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 ID                                        NOT NULL VARCHAR2(47)
 COL1                                      VARCHAR2(47)
 COL2                                      NOT NULL NUMBER(10)
 COL3                                      NOT NULL NUMBER(5)
 COL4                                      NOT NULL NUMBER(1)
 COL5                                      NOT NULL VARCHAR2(1)
 COL6                                               NUMBER(3)
 COL7                                      NOT NULL NUMBER(1)

expdp user@datab_a TABLES=schema_a.tab_a DIRECTORY=dir_a LOGFILE=log_a.log