Comcast Time Warner Cable logosTime Warner Cable execs sounded pretty darn sure of themselves last week when they told investors that they believe Comcast’s $42.5B acquisition agreement will fly in Washington and benefit shareholders. But the No. 2 cable company had to be more measured in its annual report, out today: TWC “may fail to complete the proposed merger with and into Comcast and, even if the merger is successfully completed, the anticipated benefits to the Company’s stockholders may not be realized” it says in the SEC-required “Risk Factors” section of the yearly filing. The deal only works if shareholders of both companies, as well as antitrust regulators and the FCC, approve it. But there’s a chance that might not happen “on a timely basis or at all.” And if the deal does close “there can be no assurance that the anticipated benefits to the Company’s stockholders will be realized.” TWC notes that it faces “certain purported class action stockholder litigations relating to the proposed merger with Comcast.” (Here’s one of them.)  It will “vigorously defend against any such claims” although “the costs of the defense of such lawsuits and other effects of such litigation could have an adverse effect on the Company’s business, financial condition and operating results.”