Stop Service before uninstalling 3rd party tool

[SamDman]

I have a basic MSI install.
I need to stop a service before CA which uninstalls a 3rd party product.
The CA is sequenced after StopServices, but checking the MSI log for the uninstall.

MSI Log
-----------------------------------------------------
Action start 12:12:43: StopServices.
StopServices: Service: Stopping services
Action ended 12:12:43: StopServices. Return value 1.

Action start 12:12:43: 3rdpartyUninstall.
Action ended 12:12:43: 3rdpartyUninstall. Return value 0.
-----------------------------------------------------

The problem is that the service isn't stopped when the CA runs. If I manually stop the service, the 3rdpartyUninstall works properly.

Any Ideas?

[RobertDickau]

As a sanity check, is the third-party-uninstall action scheduled for deferred execution?