third-nitro

According to this post, when your average WPM is below a certain threshold, you can’t use as many nitros. Here’s exactly what it says:

“Moving forward, the 0-10 WPM race band does not get to use any nitros, 11-20 can use one, 21-30 can use two, and 31+ can continue using all 3. We will evaluate these thresholds and will most likely adjust them up, requiring even faster for 3 nitros.”

So it would appear that you fell below 31 WPM, and could therefore only use two nitros.