If you are sued, then post details here (it is public then) and the community may be able to assist. Adding to your patent portfolio as a defence is also a good idea. Your enemy is also going to do this.
You can also sue because the grant process that involves external reviewers probably makes these reviewers sign an NDA. This competing company may be fraudulently volunteering to review cases to get advance warning of up and coming competitors - more chicanery.