The case of the missing control premium.

It's helpful to spend some time looking at the control premium attributed to the market value of a Cellestis share. The IE says that

Notwithstanding the relatively wide dispersion of control premiums observed in our study we consider the control premium range of 20% to 40% to be representative of general market practice..

..we consider a control premium at the lower end of the range to be appropriate for Cellestis

This leaves the reader speculating on what exactly might be "appropriate." 

However RSM Bird Cameron spent some time on the matter and

performed an analysis of successful takeover offers and schemes of arrangement (“offers”) made between 1 July 2005 and 30 June 2010, for companies listed on the Australian Securities Exchange.

They found that different industries demand different control premiums

Clearly the business of Cellestis is not comparable with those of real estate, diversified financials and banks. Apples with oranges. Had Cellestis been compared with similar industries we might have arrived at a different opinion

Final words from RSM Bird Cameron

Control premiums vary significantly by industry and it may not always be appropriate just to use the widely accepted average.