Maybe your airline isn't in tune with the new philosophy of Flight Standards via the Administrator.
It isn't a 'maybe', it is already in place and operating.
It is overall good news.

This incident is not going to result in any type of action that so many might have feared in the past. ASAP is perfect for this situation I agree.

If anything comes from this I bet you there is a letter issued to the operator and individual to conduct remedial runway incursion or ground safety training. I've seen this a few times with the new flight standards philosophy.

I wouldn't worry too much about it. A couple of years ago, we had a lost comms situation going into MDW where we couldn't hear anything on 130.00 MHz or lower. We immediately squawked 7600 and proceeded VFR towards a different airport that was more practical than MDW. We reestablished comms after being NORDO for about 15 minUtes by using the satellite phone to call ATC and getting a higher VHF frequency that worked. During that 15 mins, we descended and turned off of the airway towards the other airport. When we landed, we had to call the ATC facility manager at MDW. He wasn't happy and said that this would be reported as an altitude deviation to the local FSDO. I told him that we were VFR after losing comms. He said that it didn't matter and that we were to maintain our last assigned altitude. He seemed pretty adamant that our "deviation" would be investitgated to the fullest extent. Long story short, we never heard a peep from anyone...

To the OP:

IMHO you've done nothing wrong. If you read back the wrong taxiway, it was the tower's job to correct you. Separation with traffic landing behind you is not your problem. If I had to guess, the tower was hoping you'd get off the runway sooner than you did, and maybe he/she had to go plan B, and maybe even send someone around. It still isn't your problem.

File a NASA form. Don't lose sleep!

Personally on my aircraft do not reply to atc taxi instructions on rollout till we are close to taxi speed. If atc wants a certain turnoff tell me on final not while I am still at 100 kts on rollout.

If Flight Standards investigates it and determines there is no violation, often you won't hear about it. ATC doesn't determine if it's a violation, that's up to Flight Standards. Of course, if there's an issue with the aircraft, they do want to know why it happened, either due to faulty maintenance or a flawed piece of equipment, so it wouldn't be strange to hear from them either.

Controllers have the responsibility to ensure accuracy of read backs (was trying to get the 7110.65 reference but this computer isn't playing along). If the pilot acknowledges with "roger" and deviates from the clearance, the pilots at fault, if the pilot reads back the clearance and it is not corrected by the controller, the controller is at fault. That said, if ever in doubt about it controllers will submit an ATSAP and pilots should submit ASAP (or NASA, etc). In the enroute environment, deviations get researched by the regional office and the course of action taken is initiated, normally, outside the facility.