Unsure of your sources on "round holes" being indicative of torpedo "hit". Most modern torpedoes rely on implosive forces rather than terrestrial impact holes you might be thinking of from solid material striking a target. Pressure and density play a role. The holes referenced are more likely the remnants of the salvage attempts by the contracted company which assisted in the recovery. The Wikipedia article is fairly clear on the presence of holes cut during salvage. [0]:
https://en.wikipedia.org/wiki/Kursk_submarine_disaster?wprov...
While the Russian Government is not well known, based on what we are told, for transparency it is not necessarily indicidave of a "conspiracy", if a cover up was attempted its more likely to save face due to the incompetence and lack of operational and functional rescue systems, four failed attempts to retrieve any remaining survivors before the final fatal fire which depleted the remaining oxygen the crew had. It is a bleak outcome and many other countries where aware of what occurred, based on sonar and seismic data etc. These countries were ready to deploy rescue efforts which were initially refused. Occam's razor per Wikipedia, "paraphrased as "The simplest explanation is usually the best one." [1]:
https://en.wikipedia.org/wiki/Occam%27s_razor?wprov=sfla1