H1B Visa Approval Pending, OPT Expired

[pandada]

Hi,

My H1B visa was filed on time by my company. H1B did not get approved by Oct 1st (there was an RFE that may have delayed it).
My OPT was valid until Nov 14th.

First question is whether I was legal to work under the valid OPT until Nov 14th or is Oct 1st is when I was not eligible to work.

My employer continued to pay me until Dec 15th. Therefore I was working illegally until Dec 15th because OPT had expired.
How can these paychecks be reversed? What are the options to correct this mistake?
What is the likelihood this 30 day work period (Nov 15th-Dec 15th) cause me any issues in future visas?

Thanks in Advance

[pandada]

Anyone know how (or whether) an employer can reverse payroll for the past couple of months?
Is this (illegal) work period going to affect any future visa or green processing for me?