"All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident." -- Arthur Schopenhauer
How do you ensure that your CI findings are accepted? The keys are preparation and documentation.
While some competitor’s actions come as surprises, the majority are predictable and, in hindsight, clues are visible. The early clues may not reveal exactly what is going on, but should indicate that something is happening at Competitor X. You may want to alert your management that several indications of a significant move have surfaced and you will be researching further to determine the details. That way, the actual event is not a surprise to them who may think that the issue is that you did not see it coming.
Document, document, document your findings, especially if the message is negative for your firm. It takes more documentation (proof points) to convince audiences of negative messages than positive ones. Humans tend to avoid the unpleasant and, occasionally, blame the messenger. Have your evidence handy so the focus is not on you, but on the competitor. As a consultant, I have found that writing up conversations with sources is very convincing for clients. While you may not have primary research, documenting your secondary sources is equally important.
Preparation and documentation will move your audience through the first two stages of truth quickly and on to responding to the “self-evident” competitive threat which is your real goal in CI.