So you're ISTj? I think the bigger question is, are you using your dual-seeking function of Fe to connect to other people? Ah haha, can you see the irony?
Just kidding, you're just trying to understand them better, most likely using Ti if you're ISTj.
And, on the topic, yes that would be an example of an INFj trying to use Te.
Functions - Wikisocion
"If someone experiences a deficiency of it in his environment, he may attempt to supply it himself, but become soon exhausted."
Does your INFj friend lack people in his life who use Te? Parents, friends, coworkers, etc?