Since precisely Mustang b55, when JavaDMK 5.1 is used to perform a com.sun.jdmk.comm.RemoteMBeanServer.setAttribute() with a wrong value, in place of the expected InvalidAttributeValueException, you do not receive any exception at all.
By wrong value I mean an attribute of type long we try to set with an int.
I assume that JavaDMK API delegates to Mustang so that it explains why I see such impact.