It isn't the first time that I received incorrect information from instructors.
I was once told (again no places, no names) and given several sheets about a particular aeroplane I wished to rent, stating that the plane had long range tanks installed. I checked the POH which did not highlight wether or not it was fitted with one or the other giving performance figures for both. The aeroplane did not have any markings either in the aeroplane or on the wings with regards to the quantity held in the tanks. So I assumed that this was correct, until the day (about 2 or 3 rentals later having never fuelled up more than just a little top up) - only about 10 hours after I passed my PPL. When I noticed neither of my gauges were fluctuating wildly anymore (as they always did), my calculations including safety buffer stated that I had just over an hour of fuel left in the tanks after a long day trip, but on the side of caution re-ran the figures with the normal range tanks (as the lack of fluctuation made me doubt the quantity left) stating that I only had about 10 minutes left (thankfully only 2 minutes from my destination which happened to be the closest airport). Upon landing I found that the plane did not in fact have long range tanks and only had a few litres of AVGAS remaining. Thankfully I had a friend with me during the checkout ground session who vouched for the information given, but I really had to fight my corner!!
This event had taught me to be wary about information given, but when someone comes highly recommended, and charges you a bob or three. Also boasts about doing people's type ratings in many HPA over a cup of tea. And gives you printed literature (which I found by the way) stating black on white that I will be flying a turbine engine driving a propeller... I didn't want to argue! To be honest - I didn't really care what was inside the engine providing that it would fly me a little bit faster to my destination & knew which temp gauges to look out for on start, during flight and shut-down as well as how to use the digital engine management system the rest didn't really matter... I now know I've been made a fool twice!!
These people are people who you trust, and the only reason you're paying them is to impart a small amount of their wealth of knowledge. So you do have a tendency to trust them... Perhaps a little older and a little wiser now - I will learn to only trust the people who have earned my trust!