In what sector?
Engineering or biomedical stuff?
In what area of the country, London?
Was this consistently applied? The usual sort of process is that scripts falling around grade boundaries are inspected and elements of performance that indicate the higher grade may be taken into account in the final decision. A straightforward upgrading of all within a certain percentage of the nominal boundary seems unlikely (unless a "natural" boundary had occured in the exam).
The only possibility I see would be if the average marks across all students in that course year were substantially below expectations based on previous years then they may bump