We know that professors are busy, and more often than not we (students) do not receive quick replies from them. However, the tables have turned (sadly, and just once).
This summer, I'm working on some advanced reading and possibly research under the guidance of a professor not at my institution (given the pandemic, all interaction is online, i.e. via email and scheduled Zoom meetings). After one of my meetings, I wrote to the professor summarizing whatever was discussed in the meeting, and heard back from the professor within a few hours (probably two). The reply also contained some information unrelated to the meeting, to which I may have been expected to respond to. At that point, I was in the process of completing certain work that was assigned to me, and I decided to reply back only after I had made some substantial progress to be able to give an update. So, I replied after approximately 60 hours with updates on substantial progress (as I had expected), and also replied to the extra bit in their email which was essentially some information besides what was discussed in the meeting.
In retrospect, I feel a little awful for sending in a late reply to the professor's email, though 60 hours hopefully isn't too big a deal. Could this possibly be interpreted badly/negatively by the professor? I intend to respond swiftly henceforth - but I am wondering if anything went wrong this time around. I haven't heard back from the professor in about two days now (that's probably okay, but still enough to trigger anxiety).
Please let me know in the context of the above situation if everything seems alright and if replying ASAP to professors is the way to go. Since many people here are at advanced stages in their careers (PhDs, postdocs, professors, etc.) - I hope to gain some valuable insights. Thank you for your patience and for reading this far!
Lastly (though somewhat less important), as the title suggests: Is it considered bad if a student replies late to a professor? (just in general, without context)