The 337 Page report is now available at the Chemical Safety Board's website. The executive summary seems quite comprehensive and readable, but a quick scan of the main report suggests that there is more to learn if you dig deep enough.
From what I have read so far, the key issues were.
* Procedures - did not reflect how tasks were done in practice, and were not really used for the startup
* Pre-start checks - a comprehensive program of checks was specified but not carried out
* Maintenance - faulty equipment was not repaired during the turnaround because supervisors decided there was not enough time
* Control system - indicators and alarms were not working
* Interface - information to carry out a mass balance was not available on a single screen (exactly the same as the Texaco Pembroke accident)
* Manning - failure to provide extra personnel for startup
* Shift handover - insufficient discussion and poor log keeping
* Fatigue - operators working on the turnaround, 12 hours shifts for 30 days without a break
* Communication - critical messages passed verbally and misunderstood
* Training - mostly on the job with no training for abnormal situations, including startup.
* Poor plant design
* Operating limits - failure to identify all key operating limits and to monitor operations
* Poor risk management - including siting of trailers and failure to remove non-essential personnel during start-up
* Multiple organisational failures - as identified in Baker report
I've also put together a more detailed summary here