URGENT help with application

[oasys]

Hi all, I just recently submitted my application for UK Tier 4 Visa and I realised I might have made an error that could be damaging to my application with regards to writing an accurate description of my purpose of visit to the UK in 2014. To begin with, in 2014, I visited the UK on a Student/Tourist Visa for 4 months. The exact purpose of that trip was to visit a university professor and talk about research projects and at the same time I did some work on a personal project that we on my own personal capacity at home (i.e the place I stay near the university). Note that I was not at all affiliated, paid or was under any kind of contract -- the whole thing was an informal interaction with the professor.

Now, in my application, I noted the purpose of the trip was "Volunteer research assistant at the [name] university". However, I realised now that this sounds very misleading in the sense that I might have spent my time in the UK as an unpaid worker which is not permitted. Now, I am very worried that my application will get rejected base on a narrow interpretation of my statement. Is there anything I can do about this? Note that I have travelled in the UK after that year and the UK borders did ask me about my 4 months stay and they were OK with it since I was able to explain my true intent of my visit.

[oasys]

Guys, any thoughts?? Does what I wrote sound misleading and lead to a refusal??? Also, forgot to mention here that my student/visitor visa allows one to stay up to 6 months