Everyone makes mistakes, even rich, powerful and successful people - everyone. Consider for example, the unfortunate experience of Michael Bay on stage at CES.
Many weighed in with their thoughts on how to avoid finding yourself in a similar situation. I say learn not only from your own mistakes, but also from the mistakes of others. Here's my take.
Toastmasters - Seriously. Everyone should have Toastmasters' experience on their resume. This tried and true, international organization can teach anyone how to be more comfortable speaking in public. They can also help you extemporaneously. Toastmasters has a lot to offer. There are clubs everyone and they usually meet for only 60 minutes, plus or minus. There's just no excuse not to be a member.
Improv - Yes. Really. An Improv troupe is a fabulous place to learn how to interact spontaneously with others. Improv is all about give and take and building on what the other(s) give you to work with. Improv is more about fluid communication between people than it is about comedy. Join an Improv troupe and you'll not only have fun but learn to be more comfortable in any situation.
Laugh - By not taking yourself or the situation too seriously, you can modulate the negative effects of any technology snafu. Make a joke; especially one at your expense. Get your audience, however large or small, to laugh with you. You'll all feel better and they will always remember how you made them feel.
In truth, mistakes are the best way to learn. The very best. Just don't make the same one twice...