Being retired from the people who will be contacting you shortly, I think there is reason for concern. You do have responsibility for the oversight of the student. A simple sign-off and its all his fault or the original CFI did a bad job, will not fly. How do you instruct? Through a school or on the side? How much time did you spend with the student, any ground school, were any written tests given or did you assume that everything the student needed to know was already covered? Depending on the workload of the Inspector, it may take days to a month or more to get to your case, but since they now have a package on the situation and especially an airspace violation and involving an air carrier, it will be dealt with. Many variables to consider and I only know what you said here but if you main concern is if you will lose your license, nope. Will you get a violation? Instruct for a bad outfit, any previous violations, have other students from your school caused problems or get asked to call atc a lot? Do you have a good attitude about ensuring future students at least have a quick review to ensure essential knowledge now that YOU are their CFI, especially foreign students which are a known higher risk due to language issues? YOU are responsible for the oversight of the student even if he doesn't do what you say, YOU are responsible that he has the knowledge needed, he's a primary student with zero certifications, he may have 100 hours and all of it bad instruction, you sign him off and while the previous CFI will get attention also, YOU were the last one with the opportunity to break the chain. There is a lot of poor instruction out there and its not always "he's just a bad student". FSDO knows this and will be quick to see where the issue really is. Maybe I'm reading your post wrong, but if you deal with FSDO by blaming the student and the previous CFI for everything and you being 100% not responsible at all, I can assure you, will get you the very attention you are so much trying to avoid.

Jedinein gave some excellent points also.