Leaving aside the question of whether or not the HSE were even given the correct information (which I understand is disputed) the fact remains that they stated that these fonts were on the limits of acceptability. Hardly a situation which anyone should be prepared to accept in a safety operation, including you people who have the task of sorting it out.
The reason there are regulations is to take away the responsibility or decision on what is acceptable from people who may or may not have varying degress of difficulties, or even motivation for trying to do something about it. How can you possible argue that anything less than above the limits of acceptability is what you must provide and quickly. There are well defined standards in the regulations. Simple.