Generation of javadoc for HippoItem throws exception

In setting the alpha tag I have to deploy the site toolkit modules to Nexus. The deploy also uploads the javadoc, so it needs to generate it first. Generation of javadoc fails on the class HippoItem.java in the content-beans module. It seems like the root cause is the method HippoItem#getProperty, because immediately after parsing that method I see

javadoc: error - com.sun.tools.doclets.internal.toolkit.util.DocletAbortException: java.lang.ClassCastException: com.sun.tools.javadoc.MethodDocImpl cannot be cast to com.sun.tools.javadoc.AnnotationTypeElementDocImpl

It seems related to this bug Javadoc crashes when method name ends with "Property"

Attached is the full stacktrace