Lots of issues here. Am an adventurous type myself though not remotely in his league. Appreciate his need not to be "caged" and that there are always people who want to push the envelope. If they did not we would still be living in caves...
However, how would the tribe concerned have benefitted from his visit? Yes, he might have increased the sum of human knowledge but what about the risk of introducing diseases to which members of the tribe would not have immunity? There was also a risk they may have objected very strongly to a visit and become violent to, in their terms, defend themselves.
Presumably his wife would have known he would continue to undertake expeditions but what about his children? On the other hand, firefighters face enormous dangers and thank goodness they are willing to do so, despite many having children.
If he had visited the tribe what about the intellectual property rights of anything he and subsequent visitors discovered? (Thinking here of, for example, the possible use of a plant to remedy or cure a particular condition which may also be suffered by people living in "civilisation"). What about the resource implications of such any such expedition and any rescue that might have been required?
Where explorers go, exploiters may follow. Not something he or anyone else could necessarily prevent.