I hope the pilot took the necessary precautions and did not treat it as a 'hop' over the channel.
As an ex RAF sea survival instructor (at Sqn level) I have posted on this subject several times in the past.
The only real precaution you can take is to have two engines. If the single fan stops when you over open ocean (Newton's Law of Universal Gravitation applies) and even if you manage to carry out a decent ditching (or water landing as we seem to call it) you chances are slim unless:
1. You have all the necessary survival gear
AND 2. you have been trained too use it in realistic conditions (realistic conditions = in the sea, not in a swimming pool)
It is the bit in bold that most people just don't get. And when it comes to discussing this with armchair experts, especially pilots that expound a view without ever having done real training, I always say this. If you haven't been chucked into a cold, dark, stormy sea from height at at least 20 miles per hour, then listen and learn from those who have.
And for the record, I understand and agree with those who aware of this and are still happy to transit single engine over the ocean. Some folk weigh life experience versus risk and embrace it. I do so myself as most of my hill-walking is solo. IMHO the equation alters however, when you take responsibility for the welfare of one or more other human beings.
The vast majority of survivable ditchings feature most of the following criteria:
Daylight
Flat/calm water
very close to land or a surface vessel
warm or mild weather/water
good drills
good training
good kit
Fly safe all.