I read your opening post to my hubby before mentioning anything about what I'd said and the first thing out of his mouth was "oh, she's open."
If she's calmed down, that's a pretty good indication that she's open, and to expect this behavior in the next heat. You could have her preg checked. I'd discuss it with the farmer. Did he guarantee that she was bred? Technically she was "exposed" unless he had her preg checked. Or knows for certain she wasn't bulling. If you've had her in a pen, you would know if she aborted the fetus. That can happen, especially when exposed to stressful conditions.
Here's some good information regarding heat detection. Both my hubby and I grew up with cattle. We only have about 90 head right now so when we see behavior we don't really think about it. I find explaining things are harder when they're second nature. Cassie already nailed what I'd like to say so I'll just say I agree with her post.
From the link I posted, your heifer was more so displaying secondary signs of heat.
https://extension.psu.edu/heat-detection-and-timing-of-insemination-for-cattle#section-3
Still watch how you handle her and make her give way to you. You should always be the alpha "animal" in every situation when dealing with livestock and pets. Animals can be silly too, but they should always give you space unless you are wanting otherwise. My husband rubs our cows and some of our bulls (the cattle are his thing, sheep are mine) but they still need to respect him.