Has he been getting a reaction to his new behaviours - not necessarily form you, but form ds1, or at school, or other relatives?
the pulling away and touching where he had bitten would, if it was dd1, be a sign she was wondering what my reaction would be (if I hadn't already reacted!)
dd1 does the public roaring too - she was at it today at lunchtime, in fact (pub lunch) - she didn't want the choice of food on offer (chicken and chps - she is fine with this meal), and kept shouting at me when I tried to run through her options (chicken, beef, or gammon - she has eaten all before, was likely to choose chicken).
we are working on a sticker system with ehr right now, to great effect - she earns stickers (this is a very new thing since Disneyworld - she is Disney Princess obsessed!), and if she earns eg 2 stickers by lunchtime, she can have raisins after lunch. so, haivng given her the chance to not shout at me, I hissed "if you carry on shouting when I talk, you won't get a sticker" and quickly turned it round with "remember ot earn a sticker, and get raisins, yuo need to talk nicely" and swiftly distracted with an activity book I had with me. thankfully it worked.
in your situation, I owuld have outlined a reward system for dd1 beofre we went (high stress activity - for me! - so dd1 woudl be bound to be acting up anyway...), and would have sternly reminded her what she stood to lose (raisins, ipad time, playing "what's the time Mr Wolf") - we ar supposed ot be working on making everythign positive, and giving he the chance to earn rewards, rather than using threats which leave us with nowhere to go, but sometmes (and this would be one of them), the urgency of the threat might work with dd1.