Leigh!  I really enjoyed the post and the comments.

I agree with Chuck that setting expectations and on-going conversation is key.    It seems that trust and respect between Juan and Robert took a dip after the first few weeks. One way to keep that trust going is with frequent conversation using the 3+1 feedback model.  Whenever you have a chance to provide feedback, deliver 3 things that were done well and 1 item that needs improvement.  This strategy maintains trust and provides a very important focus on 1 thing to improve.  Monitor performance and provide guidance on that one item until it isn't an issue anymore.  Then do another 3+1.  Providing more than 1 item to improve often demotivates and creates a negative outlook on work, as it seems it was with Juan.

This is a great tool: makes it easier to give improvement feedback, and it is lovely to receive! And it is great if feedback wants to be seen as being delivered with kindness.  Training all staff on this strategy, doing it early and often (manager to staff, staff to manager, staff to staff) helps to create an environment where performance is recognized, and the opportunity to learn and improve is welcome. A 3+1 feedback tool is available for free download here:  http://readytofeedback.com/RTFFeedbackForm.doc
Thank you for offering me the opportunity to comment!  Looking forward to your upcoming posts!

Sonia