There are music police everywhere you look. Fortunately they have little authority. There is a wide range of styles in Irish music, some very highly ornamented and some hardly ornamented at all.

On the other hand, if you are playing in a session you need to find out what the preferences in that session are. Some musicians are very territorial and some sessions are notorious for speed and snobbery. Others are exceptionally open and friendly.

I would suggest that you listen to a lot of traditional music. Phrasing is very important in order to make the music sound Irish.

Finally, I would not rely on the comments of a single person as to your contribution to the session. Talk to some of the other people too.