Ann: Change of Director's Interest Notice, page-70

PC's SMSF was not the seller of the shares; it was his investment trust.

My reading of it is that he's freed up $100K in the investment trust so that he can make a non-concessional contribution to the SMSF of that sum. The maximum non-concessional super contribution is $100K per annum.

Using that contribution the SMSF will then pay the tax liability arising from the issue of the performance share to the SMSF.

That share issue happened in the 2019 tax year and, as PC has probably lodged his SMSF tax return in May with an extended lodgement deadline through his tax agent, the liability for the tax in the SMSF has only just now materialised. But I reckon the biggest motivator in selling the shares in June is the timing of that $100K non-concessional contribution.