Author: P. Aarne Vesilind, Duke University.
There is a big difference between engineering and science, even though engineers often work in the same environment with scientists. By their nature and training, engineers seek to "make things work" or "make knowledge useful." They are far less likely to seek personal credit, because the true joy in engineering is watching something happen, creating something that was not there before.
When Jack presented his seminar to the Chemical Engineering Department, the engineers in the audience did not care nearly as much about who did something as they marveled at what was accomplished. The important thing was the fact that Jack was able to put it all together, to tell a whole story, even if parts of it were written by others.
Obviously, Jack should have acknowledged the contributions of Bob and his mentor, and to fail to do so would have been an oversight. But the job interview seminar is quite different from a formal presentation at a national conference, and the credit given with the concluding slide would be considered appropriate in these circumstances.
In summary, Jack is not guilty of unethical conduct. The important lesson to take away from this case, however, is that acknowledging the contributions of your colleagues does not subtract from your own work, especially if you are synthesizing the information and telling the whole story of how you (plural) "made things work."