It comes down to irresponsible end users. If they are able to successfully sue an open source developer for a bug is besides the point. If the end user cannot comprehend use at your own risk, they are in much deeper trouble and the resulting lawsuit victory will not help them in the long run.
Submit a bug report and be helpful about it. With bugs in open source software you can become the number one enemy of the developer(s) you sue, or you could potentially be credited in the subsequent release. Seems like a no-brainer to me...