The people advising taking the lane are more certain about it being a better option in this case than "speculating" would allow them.

No one complained that those people were speculating.

We know he did reasonably OK with what he actually did. It's the alternatives that people are proposing that are speculative.

It's a risky road in any case. Taking the lane isn't magic.

That's more like wild speculation.

If the driver did see him (and hit him deliberately?), then taking the lane wouldn't have likely made things better.