This is a clear bug identified in the community which prevents the targeted removal of scheduled message by an administrator.
This was fixed on the 2.4.x branch of HornetQ via commit b1c339d1bddab402ffb49402a5e1ea8d1a37927c.
Justin Bertram <email@example.com> updated the status of jira HORNETQ-1367 to Resolved
Clebert Suconic <firstname.lastname@example.org> updated the status of jira HORNETQ-1367 to Closed
This was fixed on the 2.3.x branch of HornetQ via commit ea2091e3ba214b267224f4acb4b08e16c092ec22.
Appears to be fixed by HQ upgrade to 2.3.21 https://bugzilla.redhat.com/show_bug.cgi?id=1132168. Setting to MODIFIED.
Verified in EAP 6.4.0.DR1.