It seems that presenting the LMAlertView from a view with a view controller that sets preferredStatusBarStyle to UIStatusBarStyleLightContent will result in a status bar style reset back to UIStatusBarStyleDefault when the alert view is visible.
My workaround is now to implement preferredStatusBarStyle with a fixed return value to LMEmbeddedViewController.m:
- (UIStatusBarStyle)preferredStatusBarStyle
{
return UIStatusBarStyleLightContent;
}