Tailings cementation is a very high cost and conservative...

Tailings cementation is a very high cost and conservative approach. It is normally used in highly sensitive environmental situations, elevated or unstable situations and similar.

Its use at Siana is in my opinion an overreaction to the tailings wall failure.

The fact that the wall failure occurred at all was unrelated to tailings stability but wall construction, controls and maintenance. That the wall failure occurred and tailings did not escape or result in any environmental impact is in itself a good argument that cementation is unnecessary.

You are correct that cementation is a requirement at present, but this can be changed if strong evidence can be shown that cementation is unnecessary