I think one of the issues with BB ... and I'm talking about any recent BB, even channel 9 and channel 7 ... is that 24 hours (or 12 hours if you only count the hours that HMs are awake) needs to be cut down and condensed in to a 1 or 1.5 hour episode. It would be extremely difficult to show, with complete context, and in full, every single conversation, drama, and/or argument that was had in the house during that 24 hour period.
As a result, we, the viewers, get "cut-down" versions of "some" of the interactions that took place during the day. Editors have to "pick and choose" which interactions they show, and how much of those they show. Not only that, but they also have to put all of this in to some sort of logical order (timeline-wise) that makes sense to viewers.
Therefore, because of this requirement to cram everything down to a 1 or 1.5 hour show, things can look, or come across as, a bit "suspect" to viewers who then jump on forums such as this one and accuse the show and the producers of "bad editing", "manipulation", "favouritism", etc. And, this is made even more prominent now that we have a live feed back again.
I am not trying to make excuses for the editing or the "favouritism" ... I do agree that things can and do look a but sus at times ... and that editors/producers can also show "showmances" or other "not-so-relevant" things ahead of "important" interactions ... but, regardless, I can at least see why we, the viewing public, get the "impression" that there is bias in the editing, when, given the restrictive nature of editors having to condense everything down, and quickly, to meet the show deadline, there may very well not be any such bias at all.