Normally by the time they are getting to the third set of amended numbers, the first officer would start a new TOLD card. However, as it was approaching the scheduled departure time, the first officer elected to overwrite the existing figures.
To all the Captains out there: Actively go about setting an environment where there is no rushing on your flight deck to achieve OTP. To all the F/O's, don't worry about OTP, there is one speed that is both efficient and safe, find it, tick along at it, things work out just fine even if you are three minutes behind schedule. YSSY probably would have slowed them up anyway.