That's horrible, and seriously unprofessional on her part. Did you catch her name? You can file a complaint for both being on the phone and for laughing at your accident. I can't imagine that anyone would be happy about an accident that happened on their land since that makes them liable if there is a related injury later. Her trying to file the paperwork may have been her attempt to make up for it later. Some people do react poorly if they have some disorder that makes them seem unsympathetic when they just really don't know how to react, but the fact that she was on the phone just suggests that she really was a poor employee who needs corrective action from her boss so she doesn't upset future customers. The fact that she managed to hit one of your triggers sounds like just a combination of unfortunate timing and reactions.

Are you okay? You said the items that fell on you were heavy. I hope you had someone with you to keep an eye on you to make sure you don't have a concussion. Hope you feel better today.