It's something I learned, or was taught many years ago.
Primarily if you are dealing with a cluster, everything should be done within the cluster manager since the cluster is monitoring the health. "old school" thought, although it appears that this has changed, is when you stop/start/restart outside of the cluster administrator, the cluster may think there was a problem, and then may fail the group over to the other node. From poking around some, that is not the case if you use Configuration Manager to stop the service from this link below. This probably still applies to 2008, 2012,2014.
SQL Server 2005 supports starting and stopping SQL Server services by using any of the following tools:•Cluster Administrator
•SQL Server Configuration Manager
•SQL Server surface area configuration
•SQL Server Management Studio
Note Do not use the Services snap-in to stop a clustered instance of SQL Server. If you use the Services snap-in, the cluster service restarts SQL Server.
I still subscribe to only using the cluster administrator to take the sql instance "offline"/"online". Your answer is technically correct.
Brian Kelly thinks this is also best practice (using cluster admin):