PowerShell Pipeline Fails Even With $ErrorActionPreference Set to "SilentlyContinue"

I am invoking PowerShell from C# and noticing that setting $ErrorActionPreference to "SilentlyContinue" seems to be getting ignored. When running in an interactive PowerShell session I get no error, but from C# I get an error about the command being invalid.

Here is the code:

        static void Main(string[] args)
        {
            Runspace runspace = RunspaceFactory.CreateRunspace();
            runspace.ApartmentState = System.Threading.ApartmentState.STA;
            runspace.ThreadOptions = PSThreadOptions.UseCurrentThread;
            runspace.Open();
            Pipeline pipeline = runspace.CreatePipeline();
            pipeline.Commands.AddScript(@"$ErrorActionPreference = ""SilentlyContinue""
                                           bogus-command
                                           Start-Sleep 10");
            pipeline.StateChanged += pipeline_StateChanged;
            pipeline.Input.Close();
            pipeline.InvokeAsync();
        }

        static void pipeline_StateChanged(object sender, PipelineStateEventArgs e)
        {
           if(e.PipelineStateInfo.State == PipelineState.Failed)
           {
             // Failure Occurred
           }
        }

The error reason is:

"The term 'bogus-command' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again."

The error is correct, but because of the $ErrorActionPreference I would expect it to be suppressed and continue on to remaining commands instead of failing the pipeline.