Ann: Acquires security advisory and Splunk consultancy business, page-26

You are tie-ing it to the wrong event! refer to Graph below.

The share price went all the way back to CR price once the market understood that ex CEO was selling shares (informed 19th march). When an announcement later came out (18th april) stating that keith was not selling any more and that another large parcel was cross traded, the market was no longer worried that there was a massive overhang and was happy to buy up as they knew there would be no selling pressure.