That frequency of friendly behaviour, by design of the whale itself, is increasing. There is a learning curve and these animals aren't dumb. But Palm believes an adverse learning curve is just as possible. Hunting would have a huge impact here. Changes in behaviour can happen quicker than you think.
Whales cry in pain just like any other animal and whales in the vicinity hear that.
Grays in particular are very protective of their young. That's why commercial whalers knew that if they got into breeding grounds and harpooned a calf they could get mum, too, because she would come running. Under attack, they were anything but docile. They reacted strongly and violently. Gray whale leaps up for a look around, an activity known as breaching.