Using version 2.0.2, seeing same results with 10.9.5 and 10.10.5, running CLI or through policy
administrator$ dockutil --remove '/Applications/Microsoft Office 2011/Microsoft Excel.app' --allhomes
item /Applications/Microsoft Office 2011/Microsoft Excel.app was not found in /Users/administrator/Library/Preferences/com.apple.dock.plist
also tried just using
administrator$ dockutil --remove '/Applications/Microsoft Office 2011/Microsoft Excel.app'
It does exist in the plist and I tried different combinations of ' ' and to deal with spaces
<string>com.microsoft.Excel</string> <key>dock-extra</key> <false/> <key>file-data</key> <dict> <key>_CFURLAliasData</key> <data> AAAAAADUAAMAAQAA0QwbhgAASCsAAAAAAC0M +AA4/4oAANE4DXAAAAAACSD//gAAAAAAAAAA /////wABAAgALQz4AAAAGgAOACgAEwBNAGkA YwByAG8AcwBvAGYAdAAgAEUAeABjAGUAbAAu AGEAcABwAA8AGgAMAE0AYQBjAGkAbgB0AG8A cwBoACAASABEABIANkFwcGxpY2F0aW9ucy9N aWNyb3NvZnQgT2ZmaWNlIDIwMTEvTWljcm9z b2Z0IEV4Y2VsLmFwcAATAAEvAP//AAA= </data> <key>_CFURLString</key> <string>file:///Applications/Microsoft%20Office%202011/Microsoft%20Excel.app/</string> <key>_CFURLStringType</key> <integer>15</integer>