I'm not sure on the subtype, but it could explain how others could see you as an ESTP.
You seem to clearly favor Ti over Se, based on posts in the past, although it looks like you probably have a good mastery of both.
You strike me as a someone with a strong bullshit detector. ISTPs seem slightly more in tune with sniffing out bullshit than ESTPs, although I suppose it could be a toss-up, depending on the individual.
You bring a clear, unbiased voice into many discussions. Either type could do this, but I thought ISTP seemed a better fit.
This seems to fit, except I was taught to pick up emotional states very easily and without any effort at all. Other then that I match it pretty good. Checking ESTp Socionics Types: SLI-ISTp
Take what I say with a grain of salt, because that's all it is compared to the ocean of complexity when it comes to actions and real life.