I'm not sure its possible to be "quite ub?r" anything, but I get the gist.
Both fish are grateful for your concern but like myself, struggle to see where your concern came from considering both were free of trouble prior to your post. We'll just need to put it down to "the internet" and its lack of personaility and/or audible emphasis I guess.
Not to be an #OOPS# about it, but although you're right about using CAPITALS TO SHOUT, let's not be naive and pretend multiple exclamation marks don't do the exact same thing.http -://www.oxforddictionaries.com/words/exclamation-mark - of the 4 examples given, you weren't being either of the last two. Something to consider for the future perhaps.
ManvFish while I recognise what you are saying about shouting etc if you look at other posts by violet she often uses exclamation marks and doesnt do so to shout.
You will also find she regularly tells it how it is and as she pointed out FK would recommend removing anything with the potential to harm/trap a fish. The fish may have been free at the point of her post but she was trying to help incase it happened again. Not knowing whether you had already removed the item or made adjustments she could only suggest removal incase you hadn't already done so.
That said I had a similar experience with what should have been a harmless flower pot in my tank, a platy one day had decided to try and swim through the small hole and got stuck leading to what I would imagine was a very stressful prolonged death. The pot had been in the tank for months before hand with no issue but just one day it happened. Pot promptly got removed and has never gone back in.
I don't normally weigh in on these things, but having just done a 3 day digital communications course for work I would like to add a few comments.
In general, things like exclamation marks do imply the same as capitals i.e. shouting or raised voice.
IMO, one shouldn't have to look through a user's previous posts to to try and find out whether they're a jerk or just "telling it like it is". Although V is a long time and respected member, so this doesn't apply to her, many people use "telling it like it is" to justify rudeness.
Best course for everyone is to take care of what they write, in other words, consider how it will come across to someone who doesn't know you and your style.