I believe if you think it was appropriate to call your lead, then it was. You're a student/orientee and still learning but.... I don't necessarily believe your preceptor was in the wrong either... It all depends on a relationship you've built while under this preceptor and your exposure to increasingly more complex cases during your training.
You mention that you're nearing the end of your 12 week orientation, but how near? 8 out of 12 in the books, or 11 out of 12? This could make a difference in my perception of the events as you've told it. Further, has this been your preceptor for some time or was this the first time they've seen you in action? Based on their response to you voicing concern, it seems they were confident you could critically think through any obstacles and knew they'd be there if you needed more.
From experience, I'll tell you that you'll be competent before you feel confident.
You would've wanted to see the positioning, the prep (abdomen down to toes, circumferentially around the legs, the position the bed to the back table for your rooms setup, the placement of lines to know what timing before the actual incision can be expected, perform the timeout so you address items like blood products in the room, what is the expected length of the case, etc. The timing of going to lunch when these were occurring is a missed opportunity for you.
Lastly, you stated that your preceptor was going to let you go pseudo solo... that they'd be outside the room. Hopefully that meant they were literally outside the room, and not out of the OR on a coffee break. This makes some difference too.
In the end, there needs to be a debrief between you and your preceptor... A way for you two to address your concerns and for them to give you feedback (good, bad, or otherwise).