I've read through the example in the rulebook on page 38 about Raymonds total score and at the bottom it says: If Eve had been the murdered, he would've recieved an extra 18 VP (15, plus 3 more for being obsessed).

It collide with the rules on page 39 concerning obsession and also the FAQ on this forum

What if my Guilty Hunch and Innocent Hunch are the same person?

* You are considered to be "obsessed" with that suspect, for right or for wrong. You can still score either Hunch individually and score the 15 or 5 points for doing so. However, if you can prove them really guilty - their Evidence total is greater than the nextmost guilty Suspect's total by 5 or more - you score both Hunches, plus an additional 3 VP for satisfying your obsession.

The reason I am asking is that I've started to create a scoring sheet to make the total score easier to keep track of, but I guess this is just another typo in the rules.

There is no contradiction, but what is unstated is that Eve was the murderer AND had at least 5 Guilt points more than anyone else.

In the sentence, the "extra 18 points" refers to 18 points more than the 5 VP from the Innocent Hunch alone, so this is identical to the 23 VP total score for an Obsessed man (15 Guilty Hunch + 5 Innocent Hunch + 3 Bonus).

Eve Innocent: 24 VP + 5 VP for Innocent Hunch = 29 VP

Eve Guilty by 5 Guilt or more: 24 VP + 5 VP for the Innocent Hunch + 15 VP for the Guilty Hunch + 3 Obsession Bonus = 47 VP

47 VP compared to 29 VP is what the extra 18 VP refers to.

If Eve were guilty but by less than 5 Guilt points, then Ray's player only scores the 15 VP for a Guilty Hunch that pays off.