An aircraft can be flown by one man and an F/O is trained quite well enough just in case the Captain becomes incapacitated, (anyway was there 2 Captains on the flight?, it does happen). A good reason for having two crew on the flight deck is to cross-check the pilot flying and to handle the radio. It wouldn't bother me at all to see a pilot leave the flight deck after such a short time, although it would be rare (it does happen though).
Working alongside UK pilots everyday I can assure you of their abilities and you have nothing to worry about.
(And when working alone some of them can forge the most deep and meaningful relationships of their lives.
)
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