In the field, your Instructor has no say in you passing or failing anything beyond the knowledge they transfer to you. What they will do is tell the CSS/WPA how you are going and if they think you are ready for a check. A number of years ago on leaving the college you were given firm dates for your sim final and progress as well as On The Job progress and final. These were set in stone and you did the checks then, oon that day, no questions asked. If you got through, you continued.
The simulator phase is a course that is delivered straight out of a training manual that every group has based around the sector specific stuff that you don't already know coming from the college and the TAAATS bridging course.
Your Instructor will be able to show you this as it is a controlled document and as a registered training organisation, Airservices has a requirement to have this process in place. Having written 3 myself, I can assuure you they are very thorough and there is a very consistent base of information they are built from. What you may find is that the actual content may not be up to date as some groups have staff issues and can't release people for the constant updating of callsigns, references and the like but the general bones will remain the same. The sim phhase is very regimented but the OTJ part is very much all over the shop and it does take some effort by you to see traffic and not dodge the hard situations. I have seeen trainees doing hour on, hour off and either bomb their check of get found out very soon afer rating with an incident.
Wiith the 'usual' process of Critical Milestones, if you failed either final check, they would consider a 2 cycle extension then another final. Fail that and you were gone. The last few years that have coincided with the recent staff shortages
, the final check for abinitios has been a case of doing it when the Instructor thinks they are ready. There have been a few of late that were checked with some doubt but their OTJ component had been way inexcess of the usual allowance in days of full staffing. Most who fail at the moment are being sent to other groups to have another crack if they show that they may have the ability to get up eventually in a different environment (radar V procedural and vice versa) and there have been a few that have been successful and some that have not. It certainly is a very new concept and I would anticipate that as the staff numbers approach what is required, these types of second chances will dry up as well.
For all you read on this web site about Airservices failings, you can be pretty comfortable that the standard of training you will receive in the field is top notch and everybody WANTS you to pass. The more bodies the better from every body's perspective. It is up to you and your ability as to the outcome.