NOW() function is not replication-safe

It says on mysql doc that NOW () function is replication-safe and they have given an example too to prove this fact that you will obtain the same result on slave as on the master.
http://dev.mysql.com/doc/refman/5.1/en/replication-features-functions.html

I'll try to prove it with an example that NOW()function is not replication-safe. Suppose Master is located in 'New york' and Slave is in 'London' and both servers are using local time. On Master you create table and insert a row as well as you explicitly set session time zone to 'SYSTEM'.

Note: Both Master/Slave are using identical version of MySQL, i.e. 5.1.47

mysql> CREATE TABLE test_now_func (mycol DATETIME);
Query OK, 0 rows affected (0.06 sec)

mysql> INSERT INTO test_now_func VALUES ( NOW() );
Query OK, 1 row affected (0.00 sec)

mysql> SET TIME_ZONE=’SYSTEM’;

mysql> SELECT * FROM test_now_func;
+---------------------+
| mycol |
+---------------------+
| 2009-09-01 12:00:00 |
+---------------------+
1 row in set (0.00 sec)

However if you do a SELECT on slaves copy you will see different result:
mysql> SELECT * FROM test_now_func;
+---------------------+
| mycol |
+---------------------+
| 2009-09-01 17:00:00 |
+---------------------+
1 row in set (0.00 sec)

The correct solution is recorded some where else, that is, the same system time zone should be set for both master and slave.
http://dev.mysql.com/doc/refman/5.1/en/replication-features-timezone.html

For example

[mysqld]
..
timezone=’America/New_York’