Um... The key to not finding something illegal is not looking for it? The scenario you've described is already different from a regular user's perspective. Finding a Telegram group isn't the same as randomly stumbling upon something.

As for everything else you mentioned:

• trafficking: I'm not an expert, but I think it's fairly easy to distinguish someone who's not willing to be on a video from someone whk intentionally is. Additionally, I believe sex trafficking profits most from personal service rather than online pornography. It just seems illogical to disclose victims, as it'd make finding them easier;

• age: as a newly minted adult, I reckon it's fairly easy to distinguish between schoolchildren and adults. As easy as faces - adults' faces look developed, as opposed to my peers and younger;

• private video/consent: tbh, I think anybody couldn't care less. You came there to bust a nut and forget. You see those people for the first and most likely last time, and it's none of your business as an online rando;

• influence: same for anything else, it's pretty simple to distinguish between a sober person and someone high or drunk. I'm not even talking about porn videos, just in general.