Several points here....
First of all, there is a very good reason why LOIs are binding. It is to head off exactly what is happening right here.
Secondly, releasing Brooks from his LOI especially after saying we would not and the 'threats' made by his mother makes us look like we have something to hide.
Thirdly, if not looking guilty we at least come across looking cowardly.
Lastly, the key that nobody is saying much about here is Brooks father. I have to think Howland went to him and asked what he wanted him to do in this situation and perhaps he requested that under the circumstances he grant the release.