unexpected query result on hot standby server

Hello

I am trying simulate hotstandby conflicts on 9.3, but without success.

I have a basic hot standby configuration - on slave just "hot_standby
= on", "standby_mode = on" and "primary_conninfo"

hot standby node works well - but I would to generate conflict

I create table bubu on master and insert there value

-- master
create table bubu(a int);
insert into bubu values(10);

-- then on slave
select * from bubu union all select 1 from (select pg_sleep(40)) x
union all select * from bubu;

-- then on master (before slave query finishing);
delete from bubu;
vacuum full bubu;

-- this should to raise conflict, but I don't see conflict in select *
from pg_stat_database_conflicts;
-- query on slave returns two rows ???

postgres=# select * from bubu union all select 1 from (select
pg_sleep(40)) x union all select * from bubu;
a
----
10
1
(2 rows)

strange - after setting hot_standby_feedback = on, previous query
returns two rows too

What I am doing wrong?

Regards

Pavel