Once a CR2 file has been opened in the Camera Raw plug in with AppleScript, I've not found a way of opening that image in the regular PS CC workspace. Would anyone would know a command to perform such action?
The Applescript support of the CameraRAW plug-in is indeed horrendously bad.
Even the support of System Events is not much better, but you can at least access the Open in Photoshop button via System Events.
In order to see what is actually accessible via System Events, you may use a tool like UI Browser.
Thanks, Max, I'll follow your suggestion
The solution turned out to be rather simple:
tell application "Adobe Photoshop CC 2015.5"
tell application "System Events" to tell process "Adobe Photoshop CC 2015.5"
click button "Open Image" of window 1
Just in case anyone is interested