Conflicting advice on time management

On the one hand:

As a leader, you want to encourage people to entertain “unreasonable ideas” and give them time to formulate their hypotheses. Demanding data to confirm or kill a hypothesis too quickly can squash the intellectual play that is necessary for creativity.

On the other hand:

[Force] teams to focus narrowly on the most critical technical uncertainties and [rapidly experiment for] faster feedback. The philosophy is to learn what you have gotten wrong early and then move quickly in more-promising directions.

From Gary P. Pisano writing on organizational culture for HBR. Paul E. McKenney emphasizes:

[S]tress-testing ideas early on avoids over-investing in the inevitable blind alleys.

But what kind of tests does Pisano suggest?

[do] not run experiments to validate initial ideas. Instead, […] design “killer experiments” that maximize the probability of exposing an idea’s flaws.