Excellent article.
[The government describes the bank as an arm’s length Crown corporation, but the legislation indicates the board will need cabinet approval for decisions such as loan guarantees.]

That makes perfect sense, all things considered, as guaranteeing a loan means assuming the risk. There would be hell to pay in Parliament if this wasn't the case. I'm actually reassured that the model projected has the power for the Gov't to do this in cases of abject need that otherwise wouldn't be funded privately.

[“The government has provided no research or analysis that an infrastructure bank can provide infrastructure investment at lower cost than the government can,” said Scott Clark, a former Finance Department deputy minister who now writes about public finance. “What analysis exists suggests that there is no clear-cut answer.”]

It was never touted otherwise, it's always assumed that the Gov't will get the most favourable interest rate possible, especially if underwriting it.