The rule below was for 28 days overstaying.
It was recently changed to 14 days, but the point is the same. As soon as your appeal concluded, you became an overstayer.
So even though you did overstay, the period lwill be disregarded by them.
Second,
overstaying will be disregarded where the applicant previously made an in-time
application, or an application which fell within the first exception above, which was refused
and the current application was made within 14 days of:
• the refusal of the previous application for leave
• the expiry of any leave extended by section 3C of the Immigration Act 1971
• the expiry of the time-limit for making an in-time application for administrative review or
appeal (where applicable),
• any administrative review or
appeal being concluded, withdrawn or abandoned or
lapsing
https://www.gov.uk/government/uploads/s ... ers-v7.pdf