Attention Non-profit Board Members: seeking opinions/experience

Three years ago I was asked to step up to become Board president of a small local nonprofit in my county. I was on the Board a short time, the President had resigned and the vice president was unable to step up. I said no twice, citing my lack of experience but was then “guilted” into taking the position with assurances I would get lots of support-which I have received. At the same time, a senior staffer needed to step up to become the exclusive Executive Director, due to the untimely death of a long time office manager/co-Executive Director. The new ED was “in training” to become the single ED in about a year-they received 3 months of training instead of 12 months, so they have been learning by “the seat of their pants”.
There have been few bumps over the last three years until recently. Two months ago, a deadline passed for a major funding contract with the county and the ED missed it due to confusion about the deadline itself-it’s a 5 year contract for services our agency provides county wide almost single handedly. The ED reach out to only me to inform me about this near catastrophe (we would have lost most of our funding) and was on the verge of resigning. I said hold on-let’s see what we can do… as it turned out within a week the county realized how essential we are and reposted the request for funding and we were able to submit our request (all documents had already been assembled etc-the ED was waiting on the notification to submit and somehow missed it the first time around) So hopefully we will be whole once the county approves our request.
The second “bump” has to do with a p/t hire-a case coordinator-hired less than a year ago- who had recently been put on a PIP-due to concerns about “crossing boundaries” with clients: giving advice, etc. which is absolutely NOT THEIR ROLE. The job was strictly gathering information, and then turning that over to a counselor who then makes recommendations and referrals for the client, sometimes to other agencies. The coordinator had been verbally warned prior to the PIP, and apparently had been doing ok for about a month. However, last week one of the co-workers received several “threats” from a family member of the coordinator. The coordinator attempted to intercede these threats by tampering with office systems. They managed to intercede all but one threat, which found its way to the co-worker targeted.
The ED at that point had no choice but to terminate the coordinator because 1. they violated the privacy of the co-worker by naming them and personal information to a family member, and 2. they tampered with office systems as well as entering a private office without permission.
As far as I can tell both problems were handled as best as can be expected-and the termination was documented.
Here is the issue I am trying to figure out.
Does the ED need to inform the Board as a whole (not just the Executive Committee) of the details of these two incidents or is it strictly “business” and not the concern of the Board. I am getting conflicting opinions…