I had the same thing happen to an M8 6X42 a little while back. Added it to a pile of scopes that need to go back, some for turrets, one to fix a crunched lens (bought it that way, and the seller neglected to mention it...) but that's the only one I've broken.
That scope had been riding in Leupold adjustables and was recently swapped to Talleys. Could have been anything, including the 338 RUM that caused the problem, but I'm guessing it was tweaking of the tube via multiple sets of rings/rifles over the years.
I wonder if I send them a 3.5-10X50 if they will "fix" the extra cm of objective into a 40mm.
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