Slipped buffers (increasing latency over time) in C8.5.20mac

A couple days ago I was doing a bit of a leisurely recording session, and we walked out of the studio to go get lunch. When I came back, any live-monitored tracks had a latency of 500+ms. I assume that somehow there were CPU spikes in my absence (I’m tracking this down) and eventually enough buffers were missed to cause that incredible latency.

Restarting Cubase fixed it, however it was rather annoying and it took a bit for the relatively large project to re-open.

So I have 2 questions:

  1. Is there a way to know how many buffer underflows have occurred since the project opened? Anything similar?

  2. What’s the quickest way of restarting the audio engine to reset this?