In the beginning of the film, Raju asks Chatur why September 5th is important to them. In Farhan's retelling of the story, September 5 is Teachers' Day and is observed in India. Chatur was humiliated during the Teachers' Day event at ICE because he was unaware that he delivered an offensive speech in front of the ICE body and other important figures. Angered at his humiliation at the hands of Rancho and Farhan (who he might've figured out were the ones who edited the speech because they gave the copy of it to him), he made the bet with only them present. Raju hadn't reconciled with the two yet and still kept his distance from them. Therefore, he is confused about what Chatur is talking about, and possibly doesn't know that there is a bet in the first place. Farhan and Rancho could have filled Raju in about the bet, but they didn't because they didn't take it seriously at the time Chatur declared it.
Farhan being the narrator of the chronological timeline makes more sense considering that from the get-go, he is enamored with Rancho's way of thinking and fully understands it, and stayed with him throughout their college days, especially their earlier years, thus knowing certain moments and information with the trio together. Raju, while undeniably close to Rancho as well, had a fallout with him that led to their Plot-Mandated Friendship Failure and later, missed most of the days at ICE due of his attempted suicide leaving him hospitalized.
Early in the film, while describing his catchphrase "All is Well", Rancho reveals that he lived in a small village with a night watchman. This appears to contradict the fact that his father apparently earns a monthly salary of 2.5 crore rupeesnote roughly equivalent to US$500,000, adjusting for inflation, and that Rancho apparently lives in a mansion, as what Virus told Fahran and Raju during his lecture after the trio crashed his eldest daughter's wedding. Then you later learn that Rancho actually grew up poor, and he only posed as the son of a wealthy family in order to benefit his employer. Raju and Farhan failed to take note of that inconsistency, and this is the first time where Rancho drops his mask of an imposter and tells the two about his true identity, even if it's just a snippet.
During Rancho and Virus' confrontation after Joy's funeral, the former presents to him a statistical report of how India is leading in suicide rates in the world and it slowly became the leading cause of death of most younger Indians instead of natural illnesses. And during Virus' three decades of service in ICE as its director, the college's ranking was around 30th but during Rancho's attendance, it was currently the number one. Given Virus' character, just how many engineering students were subjected to constant pressure enough to kill themselves like what happened to Joy Lobo, or threw happiness and morals out the window in favor of gaining material and societal prestige due to Virus relentlessly upholding such a draconian policy?
Pia's mother was already dead by the events of the past timeline. We don't know the cause of her death or when it happened, but if she was still alive when her son committed suicide due to not being able to put up with his father's pressure anymore, then Death by Despair is in order. Or if she was dead to begin with before her son's suicide, she might have served as Virus' calming influence and even his Morality Chain, until he became stricter in raising his children and shaping them into what he wants, even if it's against their wishes. Or, if she was just as strict as Virus, if not stricter, then her husband just continued what they believed was right.
