SQL & PL/SQL

from this thread 2146662

create table testT(Val) as
select 1 from dual union all
select 1 from dual union all
select 5 from dual union all
select 7 from dual union all
select 7 from dual union all
select 7 from dual union all
select 9 from dual;

select count(*) as eachCnt
  from testT
group by Val order by 1;

eachCnt
-------
      1
      1
      2
      3

select count(*) as groupCount,
max(count(*)) as modeCnt
  from testT
group by Val order by 1;

groupCount  modeCnt
----------  -------
         4        3

count(*) returns different values !!!
My question is whether this with/withOut nested Agg function SQL behavier is documented or not.
If it is documented Please teach URL.