Is it ideally correct to benchmark neo4j as graph processing platform?
No

As Emre has rightly pointed out, the Chief Scientist of the company himself has written a blog post claiming the same.

However, Neo4j does a lot of computations which graph processing tools can do. In fact, it does graph traversals much faster than giraph, due to the Hadoop overhead and also as it stores the adjacent nodes in a doubly linked list.

So, it's not rare to confuse Neo4j with a graph processing platform (thus the claim in the paper) due to it's overlap with the features of a processing platform like Pregel and Giraph.