If a program crashes, it is – by definition – a bug with the program. In an ideal world, a program should gracefully handle everything a user requests of it. There are no exceptions to this “rule”.
Thus, because you can make LibO crash, you have found a bug. First things first, it’s now 3 months since you’ve asked this question, and LibO 3.5 has had several updates. Install the most recent version and see if you can still trigger this behavior. If not, great! (As the LibO 3.6 release is just around the corner, you might also try the release candidate version.)
If so, however, then please check if this bug has already been reported. If it is yet unreported, then the LibO community (of which you are a part!) would appreciate you reporting it. Please supply the smallest example file you can along with exact instructions to trigger the bug.