I have had exactly that happen to brass enough to know that it's not some crazy, inexplicable or dangerous event. There are two places I see it most often...
One is when I'm building hot .38 Special loads. I have a specific use for these loads that most do not (and many make wild, passionate arguments against...) but I use them to run my Coonan with the lighter 10-lb spring. And they are slightly over published max for +P loads and I typically make a bunch of these in the WORST and cheapest .38 brass that I have because I know I lose some of the brass. That brass is a large pile of S&B brass that I purchased in a lot. It's cheap, thin, CHEAP brass and I do have exactly those splits. No, not all of it and some of them have been loaded 6-8 times with exactly the same load and no split, but many of them do split that way.
The other .38 brass I can split the same way is R-P nickel plated brass, and I don't need a really hot .38 load to do it, either. It's thin brass that I bought in the early 90s. It's old and been used dozens of times. Every time I load this lot of brass I know that some of them are on their last trip.
And the other instance where I make splits like this is in .327 Federal Magnum making full loads with jacketed bullets. This is a 45k PSI max cartridge and (especially when I'm using the nickel plated brass) I can split 'em the same way.
In both cases, the crack sometimes gets to the mouth but usually does not. I've never seen it get anywhere near the case head, I've never seen it leave any brass chunks or remnants in the chamber and I've never seen chunks of brass actually ripped or torn off the cartridge case.
Extremely easy to find and remove simply by the noise they make. With the revolver, I get rid of them during ejection. With the Coonan, I usually get rid of them after they've been tumbled and I'm sorting brass by headstamp.
In the case of these .45 Colt loads, I would chalk it up to the fact that if it's REMINGTON in any way, it's a business entity that has been derailed by craptastic corporate ownership and anything/everything associated with their name is (and has been) on a downward trajectory.
I use lots of R-P brass because I -have- it already. I wouldn't spend money on that stuff, it's absolutely substandard.