It is possible that they both mishandled documents. However, that is not being claimed by the Inspectors General.
http://www.cnn.com/2015/07/24/politics/hillary-clinton-email-justice-department/
The inspector general for the intelligence community has informed members of Congress that some material Hillary Clinton emailed from her private server contained classified information, but it was not identified that way.
...
The four emails in question "were classified when they were sent and are classified now," spokeswoman Andrea Williams told CNN.
So, yes, the inspector general is claiming that Clinton mishandled confidential documents. Clinton, on the other hand, is claiming that she never handled any by email.