Lord: Upon finding out about important person in his territory, immediately sent messenger to her.... NOT Guilty... probably.
Well, he is the lord and he picked the messager. He is
at least partial responsible. (Not "partial" because he is indeed the lord.) Even if he didn't mean ill and just wanted to share some nice cups of tea. If he is all wichy-washy and picks such people as representives, he's also bad for his fief.
You could also excuse the messager: Maybe his daugther brought home her first boyfriend and he didn't like him, putting him into a sour mood and making him short tempered. It's still not excusable.
We can also assume the innkeeper didn't force those infomation upon the lord (while it might be a possibility to curry favor with him), but it's more likely the lord "nicely" asked him at some point to inform him (, which I also might have done in his place, now that I think about it).
Welp, in the end it's still: lord's hire, lord's responsibility. Those are the rules of feudal systems, alright.