A friend of mine pointed out something here in the order of the events;

insert 1 -> triggers -> insert 2

I have confirmed this by changing the inserts from my sample code as follow;

insert into T2(PK,T2C1,T2C2) values (0,30,40);
insert into t1(pk,t1c1,t1c2) values (0,1,2);
insert into T2(PK,T2C1,T2C2) values (0,10,20);
delete from T2 where T2C1=30;
commit;
and here is what i got;

1 rows inserted.
1 rows inserted.
1 rows inserted.
1 rows deleted.
committed.
T3C1 T3C2
---------- ----------
1 2
30 40

That seem to show that the "commit" has nothing to do with my trigger at this point. Also that any operation done before the trigger should be available, but the operation after, even before the commit, are not.