"The court also observed that if a case should be registered, the law should be amended and should be passed in the Legislative Assembly."
https://www.thenewsminute.com/article/can-t-book-drivers-talking-mobile-while-driving-kerala-hc-police-81404
If these last two paragraphs in this linked page is not followed immediately by authorities, such comments by honourable court could easily be misinterpreted and worse, misused. This can easily be considered as a permission to text too, so long as the driving is safe.
It is clearly observed that those who drive while talking over mobile phones, especially holding them in their hand, cause slowing down of vehivle and of traffic. It can be said with very high certainty that an unrealistically slow driver is talking over mobile. Even car manufacturers have started implementing engine immobilisers.
But enforcement?
Had read in an article long back, that a US court had cancelled case against a man who had phone on his shoulder while driving ... It is a common sight with two wheelers in India. While shifting the load to one handle, this could cause a difficult manoeuvre in emergency. Ah, well, the other handle is reserved for helmets! Here is one avenue where the statement of honourable HC can be misused, unless, as quoted earlier, laws are amended.
Besides, depending on the importance of call, it could distract the driver resulting in hazardous conditions. Needless to talk about texting. As a quote says "everything can change at the blink of an eye". Seems like the grounds on which the case was filed were not solid enough...or is the motor vehicles act still incompetent to deal with use of mobile phones while driving ? Wake up authorities, before it is way too late.
Questions remain: what if hands-free is used? What if the phone is remotely operated? What if speaker phone? Well, the best bet is not to use phone at all. Or to keep mobile phones reserved to talk while walking (no, not on road), sitting, lying or while in parked vehicle (not in traffic). Stay safe, live long, let others live too. Besides, it saves considerable time if we won't get ourselves booked and later spared after a series of legal tussles.
https://www.theweek.in/news/india/2018/05/16/talking-on-mobile-while-driving-not-illegal-says-kerala-high-court.html
The following link is informative, but how well it would work in a country like ours where everything is taken for granted, is yet open to disputes: http://www.ncsl.org/research/transportation/cellular-phone-use-and-texting-while-driving-laws.aspx