When ID's are reused in the DB, it is possible for audits to reattach themselfs to newer objects with the same ID.

for example:

PuppetClass id 123 created, had audits referencing to the 123 id.
later on, the class is deleted, but audits remain in the db.

a year later, a new class is created, which reuse the 123 id.
new audit is created, however, when asking for all audit revisions, we get back the original audits too.

workaround, filter audit search based on timestampes, for example

p = Puppetclass.create :name => 'hello'
p.audits.where("created_at > ?", p.created_at)