Hi Richard,
Very good observation, and actually in responding with the detail from that particular reference, it was placed in the sense that this account, is indeed quite questionable. It may well be remembered however, that although the official proscription of weapons did not take place until after the '45, at least not in the degree typically recorded, there was a great deal of tension in Scotland in the times between the '15 and the '45. MacGregor had been in a great deal of trouble, and being in his 60's in 1734, probably no longer regularly wore his weapons. Naturally, the veracity of this depends on which account or literature you are reading.
In reviewing this particular account, my suggestion was that MacGregor, probably would not have thrown a sword into the lake, even if it wasn't his own. The suggestion in the account that he did, was probably added to amplify his anger and dramatize his realization that he was no longer the stalwart warrior he had been.
Though I question the accuracy of this reference, it was included here to establish it as a matter of record in the discussion, and that is clearly disputable.
I completely agree, I'm extremely glad that Paul pursued the location of this most important sword and rescued it from further deterioration. It makes my heart glad to see these wonderful old warriors saved!!
All best regards,
Jim