|There are two problem areas that need to be addressed here, namely your co-manager and your own manager. |
You should meet with your fellow manager and tell him you are concerned over the way he may have presented your comments to your manager. You should find out exactly what he said, but realize that it is possible that he conveyed your thoughts accurately and your manager misinterpreted them. It is also possible that he is not being honest with you when describing what he told your manager. Either way, tell him that you want him to provide your manager with an accurate portrayal of your original comments. His action or inaction will tell you a great deal about him as a manager and as a person. In the future, you should email a follow-up note whenever you convey important information to him.
The next step is for you to give your manager the facts. Since he “tore into” you after only hearing one side of this story, you should also let him know how you feel about this type of reaction and suggest that he bring you into the loop in these types of situations. Tearing into employees is not acceptable managerial behavior, and perhaps some of the changes in your company should focus on him.