The article doesn't explain the experiment very well, which has caused confusion for myself and other commenters here. Having read the actual research paper, I'll try to outline how the experiment works, as I understand it:

Children were shown a video on a laptop featuring two containers. There would either be a helpful person or an unhelpful person who secretly puts a toy in one of the containers. The helpful person would then indicate which container they had put the toy into (either by pointing to the container or by lifting the containers to reveal the toy). Contrary to what the article says, the unhelpful person simply did not offer any sort of hint. The child would then be asked to select the container the toy was in.

I hope that clears things up.