Honestly (as an examiner/chair) - yes.
This does not mean they will not be objective. The presumption you need to address when sending a written document noting the corrections/actions taken, is that you rushed them. Usually, when a panel issues majors (which would be typical, if you have 12 months) is that the conclusion is that there is a significant problem but it can be fixed within the timeframe stipulated, based on a normal working pattern.
The long and short of it is, you should be very confident you've addressed the points raised in the R&R fully, and with careful consideration. The vast majority of PhD examiners have no interest in failing a student, but if they suggested a 12 month correction period would be suitable, and you claim to have done it in 3, it will naturally attract more attention to whether you've genuinely addressed the problems or glossed over them.