They do the same thing in different ways, where you add 2 kills for only TK while his code always gives + 1 for any kill.
Your code can be cleaned up a bit:
PHP Code:
public Death(id)
{
new killerid = read_data( 1 )
new victimid = read_data( 2 )
if ( is_user_connected( killerid ) && ( cs_get_user_team( killerid ) != cs_get_user_team( victimid ) ) )
{
set_user_frags( killerid , get_user_frags( killerid ) + 2 )
}
}