On some agency websites, the submission guidelines state that should an agent turn down a query, the author is allowed to re-query another agent at that same agency. What happens after a full or partial manuscript is requested? If the first agent turns you down after reading your full/partial, is it still okay to query another agent at that same agency?
There's no right or wrong answer to this since it depends on the individual agent and agency involved. My advice is always to Query Widely. That means if they don't say "don't do it" then go right ahead.
I'm always looking for good projects. If one of my colleagues was short-sighted enough to miss your brilliance, well you should have queried me first, but at least query me second.
Don't be afraid of offending agents. There's no blacklist, there's no such thing as the Query Police. There are couple ways to shoot yourself in the foot by querying stupidly but you're clearly not in that category.
If you spend a lot of time fretting about doing the right thing, you're going to miss out. Be bold. Query like you have the answer to my prayers.
In fact, this is important enough to be included as a Rule for Writers: Be Bold.