HKEX's largest shareholder is the Hong Kong government. They have 6 of the company's 13 board seats and HKEX's current Chairperson was appointed by the government about 18 months ago.
Being the largest shareholder of HKEX does not mean they're the majority shareholder. Every ownership percentage you've quoted from Bloomberg is an aggregate across multiple investors except the 13.78% owned by the government.
I suspect you assumed largest meant majority because of the number of board seats the government controls. Interestingly, it appears that's unrelated to the government's financial stake in the entity. Securities laws in Hong Kong permit the Financial Secretary (a member of the Executive Council) to appoint up to eight board members. The government's authority over HKEX board appointments is outlined in Section 77[1] of the Securities Futures Ordinance.
I don't think it's a lie, you've just misunderstood "Largest" to mean "Majority". The government is probably the largest individual shareholder, unless Reuters made a mistake.
You apparently have a bloomberg terminal in front of you (They are rather expensive) but you dont seem to understand what "Largest Shareholder" means? Then you say it is a lie?
Can you use your bloomberg to find ownership by individual firms and see if any single holder exceeds the 13.78% the government holds according to your post?
Press release on the "government appointment" of Cha to the board here: https://www.hkex.com.hk/News/News-Release/2018/180212news?sc...