No this would not be insider trading. You have no idea if these people even work for Splunk. And they could have just been speculating. The SEC could still sue

No this would not be insider trading. You have no idea if these people even work for Splunk. And they could have just been speculating. The SEC could still sue you and turn your life upside down by investigating every aspect of your life to try to find the connection that gave you that information, but if they can’t come up with the proof then eventually you would be fine.