I don't know how fast it can go but I suppose it can't run very fast.

Not at all, dogs are individuals :) One that's not so mellow, or with less socialization, could have reacted quite violently or fearfully (or both). Even the same animal might react differently according to his or her mood, too.

You never know. You can anticipate, but you never know. But I'm sure the robot has been tested several times in similar situations :)