Mohan got worried seeing injured Gungun, upset with ladies cat fight going on, anxious that asylum staff came to take R with them, then shocked seeing R hit his mom badly before his eyes plus abusing her verbally.
All this was happening on a danger zone road of sanctuary with tiger still roaming around them..
Here R does her regular crying, shouting, emotional blackmailing & guilt trapping M with long lecture, as if he forced her to enter into his life & his house and settle permanently with them by forging relationship with M G. So now she blames him and leaves.
All things R thought, felt and did right from she turned 18 years old, have been her own wishes, choices & decisions so Mohan or her father are not responsible.