Is Your First Conclusion Incorrect?

In 1912, Miriam Pierce had a Presbyterian minister write a letter on his office letterhead to the US pension office inquiring about a military benefit. I assumed that she had the letter written by the minister solely because he was a minister and might lend more credence to her claim. 

While that might have been part of it, it turns out that the minister was her son-in-law as evidenced by a census enumeration from 1920. My initial conclusion didn't include that possibility.

Is there a chance that your initial conclusion is incorrect?