[wenc]

In your example, the primary difference for me wasn't so much active-vs-passive, but attribution. I've seen the passive voice used to great effect for softening statements and avoiding the assignment of blame/other undesirable attribute.

Instead of "Chris and Jack disagreed during the discussion", one could say "No agreement was reached during the discussion". One may say this is mealy-mouthed, but it seems to me that managing emotions is a supremely important part of being a good communicator and being a consensus-builder. Avoiding the use of language that triggers "fight-or-flight" responses is very useful in many situations.