Massey Energy just released an updated “Letter to Stakeholders,” following up on a similar document it provided in the aftermath of the April 5 Upper Big Branch Mine Disaster.

It’s more than 6,600 words long, and probably deserves a closer read. Much of it repeats previous Massey complaints about MSHA regarding ventilation plans and the ongoing probe of the worst U.S. coal-mining disaster in 40 years. I’ve linked above to the entire letter, so you can see it for yourself.

But there were a couple of things that caught my eye and are probably worth pointing out.

First, Massey included this information about revisions to its previously reported corporate-wide safety record:

In the aftermath of the April 5 accident, Massey began a meticulous review of the Company’s accident reporting at all of its facilities. The results from this review have revealed errors in previously reported non-fatal injury rates (NFDL rates) for Massey operations from 2007 thru 2009. Massey’s review resulted in the following adjustments:

— Massey’s NFDL rate for 2007 increased from 2.05 to 2.63;

— Massey’s NFDL rate for 2008 increased from 1.94 to 2.52; and

— Massey’s NFDL rate for 2009 increased from 1.67 to 2.33.

To check the validity of its revised NFDL rates, the Company engaged its independent registered public accounting firm to test the underlying data relied upon by the Company. While the Company is disappointed in the lapses in its reporting procedures, it recognizes that the revised NFDL rates for the 2007, 2008 and 2009 calendar years still rank better than the industry averages for those annual periods. The Company is working to ensure that similar reporting errors are avoided in the future and Massey remains committed to putting the safety and health of our miners first.

And, then, there’s this information about what Massey describes as “mistakes” at Upper Big Branch:

While the investigation into the accident is a long way from being completed, Massey nevertheless has been studying it closely for lessons that can be learned — and applied — as soon as possible. We have discovered mistakes that were made at UBB and have moved to fix them. While we do not believe these mistakes contributed in any way to the accident, we are disclosing them in the interests of transparency and accountability:

— Track that should have been removed from the gate road of the longwall was not. It was not against the law to leave it, but there was a risk in doing so because it can provide a pathway for an electric current.

— Some non-permissible equipment was moved on that track, both by Massey members and MSHA representatives. This may have been the result of confusion for some people who may not have known that recent ventilation changes had altered what was permissible.

— In some places, air-lock doors were used rather than overcasts to route fresh air past neutral airways. While this was not against the law (MSHA fully approved the doors and routinely passed through them) it violated Massey best practices.

Massey also said this to say, regarding the issue of methane outbursts and cracks in the Upper Big Branch Mine floor:

During their post-accident surveys of the longwall area, team investigators have discovered several cracks in the UBB mine floor. One particular crack is directly underneath the cutting drum of the shearer, which could have provided the spark necessary to ignite gas escaping from the crack. Massey team members believe this 36-foot long fracture in the mine floor was a possible source of the methane inundation. While MSHA officials have prematurely dismissed the crack as a possible source for the methane inundation, Massey investigators continue to analyze the floor rupture and other relevant pieces of evidence. However, MSHA has been fully unwilling to allow Massey experts to investigate the crack and has intentionally disturbed it, damaging a vital piece of evidence. Their actions are difficult to understand, particularly given the previous known episodes of methane outbursts from similar cracks at UBB and nearby mines in the same coal seam. Notably, another mine in the same region as UBB, experienced a similar outburst around the time of the April 5 accident.