If you had put an entry in the Tech Log, rather than a note on the tech log, something would have to get done.
Even if it didn't encourage a maintenance check, there would be a record for future reference, especially if it happened again. That would hopefully trigger an engineer to suspect there might be a mechanical cause.
I appreciate that snagging an aircraft can have other implications (non-availability, no engineer on site, disrupting the training programme, upsetting the engineer ('cos I am one), upsetting the instructor etc) but you obviously feel strongly about the occurance and have concerns or else you wouldn't have posted.