You might need to get Bob in on this , but the company should have a duty to protect you from this and take action as appropriate .
They might have set themselves up by admitting there was a problem but not doing anything about it ..but again i am not an employment specialist ..
Definitely appeal the decision not to do anything as if anything happens further down the line , then you have it on record that you have done everything in your power to resolve the issue .
Rich :(
"The difference between 'involvement' and 'commitment' is like an eggs-and-ham breakfast: the chicken was 'involved' - the pig was 'committed'."