I am still on the fence about this one. She initially thought it was a truck engine running. Many people fit the story to the crime for a bit of attention, or a for a bit of excitement.
I find it somewhat odd that she said she saw a man and a woman without elaborating. Most people would have said where they saw them, they were on the machinery, or walking away from the site, or near a car. She heard something. Was it really for half an hour? Was it a truck idling or machinery? Why the lack of details about the man and the woman she saw, were they tall or short? I am on the fence and l am leaning towards she heard something and her account had a bit of embellishment as it happened the night before her disappearance and local gossip would have it that BM worked on the site. MOO
I have a different opinion based on what the woman (MB) reporting the construction machinery/engine noise said. This relates to other points she made which could be readily corroborated (or otherwise) by LE.
She reported visiting the building site the next day to ask the workers whether they left machinery keys on site and was told that they sometimes did, but that they were hidden out of sight. She was being a watchful neighbor, concerned about what was going on at the construction site out-of-hours, and she was interviewed by police after reporting this.
LE is the best placed to know whether or not MB "embellished" her story and they'll be able to do that by comparing what she said during police interviews with subsequently reported comments.
Another point I'd like to make is that MB reported hearing the noise continue for around half an hour. She also stated that the noise had woken her up. We do not know how long she was asleep before the noise woke her up. That would depend on many factors, including what stage of sleep she was in, whether she had taken night sedation, had alcohol before retiring, etc. We cannot make the presumption that the machinery was being operated for half an hour at most. Many, if not all of us at some point in our lives, will have incorporated real, external sounds into what we are dreaming about before we are fully awake, while our brain tries to make sense of the noise. The type of noise can make a big difference too. Something sudden, loud and atypical - such as hearing gunshot is more likely to startle someone into waking up. This woman lives next door to a building site and machinery noises will be commonplace while building work is going on. Sometimes we can justify or make excuses for such noises occurring outside their earlier defining parameters. We often recalibrate our thinking further down the path - again, a common phenomenon -especially when our brains are busy processing other information of greater priority.
A typical example of this is something that happened to me only yesterday. I saw a colleague/friend I hadn't seen for a few weeks who works a regular rota at the hospital I'm in. It was great to see her during her scheduled duty hours. I justified to myself that she was on duty as it was her normal working pattern. Only it wasn't. And logically, I knew it wasn't. I hadn't paid it any attention - I'd deemed her appearance non- significant on account of its normalcy.
It was in the evening when my mind/brain wasn't quite so busy with other things that I found myself thinking "hang on, that's not J's usual shift pattern - she doesn't usually work that time" I obviously would have thought it atypical pretty much straight away, that had she turned up on duty not ever having worked there before! (like the gunshot analogy).
It was only when my brain/mind was unpacked of other higher priority items and was "quieter" that I recalibrated my thinking accordingly.
I'm curious about another point you made: i.e. the report that MB saw a male and female on the construction site around the same time she heard the machinery noise. I haven't seen this before, so would be really grateful for a link/reference so that I can read about it further (thank you in advance).
My comment here relates to there being a question mark over the paucity of information about these two people.
The fact is that we - the public - are not automatically entitled to any of that information, especially if LE has deemed it sufficiently significant that they need to withhold it, as to release it might put their investigation in jeopardy. If they've intentionally kept it quiet, they'll have good reason for doing so.
I'm very much on the side of LE doing this, and see it as a hallmark of professionalism and informed decision-making on their part. The integrity of an investigation must always take precedence.