That's usually no big deal - that piece becomes a good starter piece for a subsequent course instead. That works as long as you don't get heavily over-subscribed in starter pieces, but you may also find a time when you have neither tongue nor groove on an otherwise usable piece of flooring. What's a homeowner to do?
In this case, I discovered that our cheap table saw makes a fine groove. It takes careful aim and tweaking to get the groove cut, and it's not likely to be perfect, but it doesn't need to be. The groove is entirely invisible supporting infrastructure for the flooring, so the fact that it may be a little wider than it needs to be or slightly rough is irrelevant, as long as the previous tongue fits into the groove and you haven't weakened the material to the point of irrelevance.
This is surprisingly painless to do, so i'm happy to recommend the process for anyone laying bamboo floor. If I have to do another one, perhaps I'll capture some video.