OK, there are two parts to this, in my experience (3 elite universities). We know that many (but not all) of the brightest/highest predicted applicants will put applications in early because of the Oxford/Cambridge deadlines. So it may look as though some get offers fast & early. And it has been my experience (but this is anecdotal and from observation) that batches of applications which only just meet the UCAS deadline tend to have more of the weaker candidates in them.
But, we do know what we're looking for, and we take each application on its own merits. There is a base line, so whether an application comes in early or late, if it doesn't meet that baseline, there won't be an invitation to interview (in my field it is national standard practice to require an on-campus interview/selection activity: no interview, no offer). And then there is a further evaluation & selection at interview.
Our decisions are never entirely individual. Together with my colleagues, I'm given batches of UCAS forms for a first selection of whom to invite to campus. My decisions are checked against my colleagues' and for consistency by the departmental Admissions tutor. Then at the selection process, two coleagues -- probably entirely different from those who read the UCAS forms in the first place, will run a selection event. And there may be two events running parallel. We all meet at the end of the day to compare notes. Our forms plus extra notes are again checked for consistency by the departmental Admissions tutor.
So one UCAS form may be seen by up to 6 academics within the department, plus central Admissions admin staff.
We also make about 4 to 5 offers for each place, although I've worked in departments where typically there are around 10-15 applicants for each place.
amillionyears: "Universities have to give equal consideration to every application received by the deadline"
Do you know this for sure?
What you're suggesting is that university academics and administrators who deal with applicants and the admission process are less than professional and contravene university regulations, a HEFCE policies of fair and transparent admissions. A rather serious accusation to make?