Is there a right and wrong way to do this

I use your mate's method.

All the best for a speedy recovery

As a roadie at heart I wouldn’t overload the front wheel and if anything would go more mtb and slide my weight back off the saddle without necessarily changing hand position and I would be reticent about the front brake unless I had to come to a stop.

TLDR you’re both wrong, good luck.

If you remove one hand and brake then it seems obvious that you'll steer off to one side. I just move both hands simultaneously. Of course, it helps to look ahead and anticipate when a braking manoeuvre might be required.

TBH I've only been riding road bikes for about 20 years, so less experience than you.

Yeah as a roadie if I don’t feel comfortable moving both hands simultaneously I would stay on the hoods and move my body weight back to balance out what I needed to do.

Also I wouldn’t be braking while holding on one handed.

Crashes happen though and front wheel wash out on fast descents happen to the best of them. Good luck with the recovery.

I move one hand at a time, but i don't brake when changing hand position. I'm never keen on taking both hands off at the same time

Hope your recovery goes well

If I get into a scrape like this, no way would I have want to both hands off the bars at once. But it does seem a bit marginal - if this things have got this messy

Dropping to the drops is not done to get weight over the front of the bike. If you've already entered the slippy downhill, leave your hands where they are, drop your heels to stop you going forward. This will help you brake without fear of your hands going over the hoods. If you know there's a tricky descent coming up, get your hands in the drops early - braking is better modulated with your index finger and leaves the rest to grip the bars for control.

Heavy elbow bend for me in that sort of situation.

And don't ever touch the front brake in dodgy situations, you'll be down before you know what's happening.

Thinking about it I always went with a sort of very fast 1-2, right hand first and then the left follows basically before the right is even totally finished moving. So not "both at the same time" but also not really "one then the other", it's a single set of movements, sort of like shifting hand grip on an axe? No idea if it's optimal but it seemed to work in all situations.

I would go simultaneously, but if for whatever reason I had to do it one hand at a time grabbing the front brake with only one hand on the bar wouldn't be the way to do it..... But you know that now.

Thanks, some interesting replies there   . I actually gave the front brake the lightest of touches for a fraction of a second but the road was greasy with light drizzle and mud from farm machinery on it . I honestly had never considered that there was more than 1 way to perform that manoeuvre

Makes me shiver, road bike crash things. Get well soon.

On the road do people run the same tyres front and rear? On a MTB I'll always run a very grippy tyre up front as it's hugely important to have that grip and the confidence it brings.

You wouldn't pull the front brake on any bike if only riding one-handed....

I think this is just one of those instances when a combination of factors, each with a tiny element of risk, come together to create a nasty outcome.

I've been riding bikes for over 60 years. I've been windsurfing for 40. So I get used to strong gusts of wind hitting me side on and have never understood why some people have a problem with deep rim front wheels on the road. Until riding past a gap in a hedge at the same instant that I was changing hand position on a blustery day.,.

It's just shit luck, these things happen. If I'm moving from hoods to drops I'll always do both hands at the same time but that's just me. Don't over think things, you were just unlucky. Hope the recovery goes well.

Is there a right and wrong way to do this

There's definitely a wrong way to do this, as you've found out!

Do you ride moto style brakes? i.e. right = front as I'm confused how you managed to "feathered the front brake" whilst simultaneously moving the right hand from the hoods to the drops....

While I'd be comfortable dragging the back brake whilst descending at some speed while changing my right hand position, I wouldn't be doing that if the road was steep or slippery or twisty...I'd just leave my hands in whatever position they are in, until the road improves.

There have been sometimes when through poor planning, I've ended up with one hand on the hoods and one on the drops for quite some distance which is a bit awkward but at least I didn't crash....

When descending on steep slippery roads (recently did this when hitting a large patch of sand covering a road and when transitioning from a road to a cycle path via a sharp s bend only to find mud on the cycle path), leave your hands where they are, weight over the back of the bike and use as much rear brake as possible without locking up and as little front brake as possible

By loading up the front wheel with weight and braking there is more chance of the front wheel sliding out from you and more chance that when you come off you will propel yourself forwards

By getting over the back of the bike and using the rear brake as much as possible (even if you have to skid) and using the front brake as light as possible you can control the bike more, worst case you can lock the rear brake hard and push the back end out and slide the bike on to its side

Been OTB many many many times over the years on the BMX, MTB and road bike,its never good especially if you dont get your hands out in front of you in time and the bike also tends to come over the top and hit you to add insult and more injury, much better to slide it out and spread the crash down one side of your body and most importantly it protects the bike much better!

IMO the issue is the one handed braking not how you move your hands