The analysis looked for occurrences of words to drawn general conclusions. It did not take into account context at all. Nor did it take into account the type of texts which were being examined. As such the comparison seems a bit simplistic and the conclusions mean little.
Scripture tends to be narrative. Narratives contain conflict, and conflicts can be violent. In particular Hebrew scripture tends to narrate the long history of a people and the conflicts they endured and engaged in order to survive a particularly violent time of human history. It is not surprising giving the genre that it would contain more occurrences of words associated with violence.
Moreover, the texts recount how the chosen people made their agreements with God, fell short of them (their trust in God) and then were forgiven and received again by God. The notion of forgiveness is an important theme. With that in mind it makes sense that "Bible scored. . . much lower for trust than the Quran"
In contrast, while the Qu'ran contains some narratives, the greater portion of it contains exhortations on morality and right or wrong living. Furthermore, a great portion deals with eschatological explanations, the end of time, the afterlife and what one needs to do to prepare for it. There is, in general, less of a need to employ violently charged words.
To be sure, violence is part of both, as it unfortunately is a part of the human conditions. Comparing the two text can yield some interesting insights. This kind of comparison, however, seems simplistic and reductive and too superficial to be useful. It may generate some heat, but very little light.