Coke isn't like alcohol - you don't simply 'sleep it off'. In fact, it's a terrifically powerful stimulant to the point where 'sleep' is next to impossible. The 'high' is fairly short lived, but the stimulant effects mean that sleep in the next 12+ hours is very, very unlikely. I've heard of people going on coke benders that didn't sleep for multiple days.
So, best case, the pilot in question would have been heading out on a long-haul flight horribly fatigued.

Thanks for the expert opinion but has anyone seen mention anywhere of evidence that he was actually impaired when he rocked up to work?
ie. was he flicking every switch, dancing around the flight deck talking bollocks at a thousand words per minute so the Capt booted him off.

He’s been a very naughty silly boy and if he takes it on the chin and jumps over the hurdles that are quite rightly put in front of him, I can see him getting back into the flight deck in a few years once the dust has settled. No need to throw him to the wolves just yet - see how he bounces back. There’s a few pilots out there with a history still flying around that this group would have burned at the stake.

It was only a few years ago the flight deck were smoking away and having landing drinks before getting stuck into Deirdre and her mates down route for a few days. Not sure airline pilots can be described as Saints and claim the moral high ground as this thread would have us believe. How many have second or third wives a lot younger than them that were CC with a bit of a cross over period.
I would also suggest the reason BA haven’t instigated drug testing of every pilot in the company ASAP is they don’t want to see the results. A minority will fail as they would in any airline and that’s only more bad headlines.

To err is human and to forgive devine. (If he earns the forgiveness)

I'd suggest the fact that he thought it was a good idea to send another member of the crew a text message announcing that he'd been taking Cocaine the night before is indicative of him being still under the influence.

As others have said - you don't just "sleep off" Coke. The effects of the drug itself and the secondary effects of your body whilst it recovers are significant and can run into days.

I really am struggling to understand the people that are trying to suggest this is not a big deal! Setting aside the drugs element (which I don't) he deserves to be sacked for being an idiot for boasting about it.

I don't know about you, but I set my standards of minimum acceptable performance considerably higher than not "flicking every switch, dancing around the flight deck talking bollocks at a thousand words per minute"!

Look at their profile. Says a lot

Dean Martin & Foster Brooks - The Bar/Airline PIlot
 

Just for fun...

The flight was cancelled before the crew left the hotel, none of the crew of the flight reported for duty that day.

Given the effects of cocaine, it's highly unlikely that he got any meaningful sleep the night before showing up to pilot a long-haul flight. That means we're talking no meaningful sleep for at least 36 hours.
I'd think no sleep for over 36 hours would leave most people fatigue impaired - even if the effects of the coke had worn off (which is unlikely that they had).
That he was then stupid enough to brag about it to a fellow crew member just reinforces that he wasn't exactly firing on all cylinders...

I wonder if Welsh and Spanish knew the rest of the crew had the next few days off??

That would not have happened. Probably the flight operated late using a FO from the inbound crew after sufficient legal rest

So after spending some time discrediting airline pilots in general , including a piece about 2nd or 3rd wives which is not so convincing as it is funny instead, you have no problem getting on the high ground yourself there by quoting Alexander Pope ... :)

Hear Hear