and in other matters
In the future I may just lie and say I've done it before
You could lie, but you may be overestimating yourself and underestimating the content you are doing.
There is a good chance you would get exposed as soon as the boss fight begins people would see that you're doing wrong, and what would lying about it then achieve for you? Get yourself swiftly kicked out of the group and start building up a reputation within the server community as a noob who lies to get into groups, possibly.
Then again in most cases there are ways by which a player can prove that they have done the content before and if lying to get in became more common and if I only wanted to take someone who has done it before, I could simply ask for such a proof.
"LFM EC come to me riding on your Aratech Fire or no invite"
How would you fake that?