Chest Pain in a Diver

Which three of the following questions about today's dive are most relevant to this patient?

His estimated depth at the start of his emergency ascent was approximately 6m. He denied active breath-holding on ascent but admitted he underestimated the duration of ascent and was unaware of his breathing pattern.

On examination, he has equal air entry bilaterally, PN resonant, RR 16, HR 65 SR, BP 112/55 SpO2 95% (FiO2 0.21).

You provide oral simple analgesia and administer oxygen 10L via non-rebreather.

Which of the following statements are true?

His CXR and ECG were normal. His oxygen saturations improved to 100% with oxygen and analgesia, and his pleuritic chest pain settled.
His case was discussed over the phone with the London Dive Chamber.

What is his likely diagnosis?