I mean okay, you were in a situation where you crossed an intersection on yellow. Technically the only time you should still be going is if you are past the point of no return and slamming your brakes may either cause on accident or leave you in the middle of the intersection.

So in that sense, it comes down to a subjective analysis moreorless. How can you know for 100 percent sure that you did not do anything wrong? And you let that affect your attitude towards the cop. You could have just moved on amicably, said "hey I thought I was past the point of no return". Cop might say " actually no you weren't and that's problematic". And you could have said " oh sorry I was focused on the road conditions I guess I just had a minor lapse there". Whatever.

If you're rude, they have 0 incentive to let you go with a warning and since you cannot know beyond a shadow of a doubt whether you did do something wrong or not (since point of no return is something people mess up a lot and is violated due to subjectivity) it's not worth doubling down on