Detect error in msi from wix bootstrapper

I'm installing an MSI from a custom bootstrapper and if there is an error installing the MSI, I want to update the UI in the bootstrapper with this info (and preferrably with the error msg as well).

I'm subscribed to these events:

Bootstrapper.ApplyComplete
Bootstrapper.Progress
Bootstrapper.Error

The Error event never fires. The Progress one is called a number of times but I only get updated about the progress-percentage from it. Finally, when the MSI has failed and returns the ApplyComplete event fires with the following values:

Is it this Status int I should be inspecting? If so, could anyone find any documentation on what the values mean?

Here's an excerpt from the bootstrapper log showing that the bootstrapper is aware that the MSI has failed:

[1A060:1A9D4][2016-04-06T10:12:09]e000: Error 0x80070643: Failed to install MSI package.
[1A060:1A9D4][2016-04-06T10:12:09]e000: Error 0x80070643: Failed to execute MSI package.
[1AD24:1D73C][2016-04-06T10:12:09]e000: Error 0x80070643: Failed to configure per-machine MSI package.
[1AD24:1D73C][2016-04-06T10:12:09]i319: Applied execute package: InstallationPackage, result: 0x80070643, restart: None
[1AD24:1D73C][2016-04-06T10:12:09]e000: Error 0x80070643: Failed to execute MSI package.

It feels like I'm going about this entirely the wrong way.

How do I get notified that there was an error installing an MSI in a wix bootstrapper?

+1, the Error handler is no longer called.

In ExecutePackageComplete, you receive a generic status 0x800703EF instead of 0. But you don't receive the returned error code from the process.

This seems a bug in wix 3.10 !