No inference needed there - he's already proven it's much stronger. He's shooting more powerful loads than the peacemaker (1873 Colt) can handle, which is a comparable comparison.
However, that's not good enough for you, since the only proof you'll accept is if the open top doesn't disintegrate with 44 Magnum loads. We've been around and around with this, and logic doesn't get through.
Just as the top strap models needed beefing up to handle stronger ammo, I'm sure the 1860 Colt is no different.
Now answer this - if the Walker can stand up to 44 Mag loads, will you agree the open top is as strong as the top strap pistols?