Who can administer me my epipen at work?

I have an unknown allergy and had to use my epipen for the first time today. As I was not capable of doing it myself my work colleague felt confident to do this so I talked her through the instructions. She did very well and was a great help. However, my boss did not seem happy she had done this and said she could be liable if it went wrong. Surely my life is more important! Are there any specific rules for administering the pen as my doctor has not made me aware of any?