Yeah, that's a little confusing.  We can talk about how we might make it clearer.  What's happening is:
*  `settingProperty` tells the modelDriver to attempt to set the property
* If the driver is blocked because the kernel has been disabled (as it usually is in this function, since it is mostly used during replication) and it tried to delegate (set another property), then the kernel's `blocked()` flag will be true.
That's what we're checking for after calling settingProperty.