While your issue happens due to a poor internet connection, mine happens because I am slow, methodical, and given to working the problems out on the paper before posting. I am not the fastest gun.
I gave up on being fastest, and have a slew of deletes either due to rushing to an embarrassing response that you will never see (early on in my experience here), or deleted precisely because my answer added zero value beyond that which was provided in other answers.
My norm now is that I pick a problem I like, and I solve it. If someone topped my potential response, and I do not respond myself, I walk away richer for the experience with another delay in brain atrophy due to lack of work on random problems in my swing set.
What Gerry Myerson said is my standard protocol. More often than not, I just never post my response due to redundancy.
You may however consider an alternative. If your response to a question really excites you, and there has been no other activity on the question, then you may consider improving your post to a level that supersedes the quality of all other posts. You are allowed to edit your post, and if you have the time and desire to modify your rushed response into a thing of top notch mathematical clarity, then you should do so. In the end the poster, this community, and the world will thank you for the effort.