Bash, command on remote server returns true in case of failed

Command executed on remote server returns true even if failed. Here is the code.

command="
sudo su - postgres -c 'pg_dump -Fc ${var[1]}'
"

if
ssh -n -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no "$username"@"${var[0]}" "$command" > "$folder_export"/"${var[0]}"/"$date"-"$time"-"${var[0]}"-"${var[1]}".dump
export_end=$date-$time
then
export=true
else
export=false
fi

I tried to stop postgres on remote server. Output shows me this.

pg_dump: [archiver (db)] connection to database "coopweb" failed: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?

But if condition returns true. I don't know why. Could be some option in ssh command wrong? Or where is the problem?

Thank you.