I've noticed that the output for bam-readcount sometimes has bases in uppercase, sometimes lowercase. This is in the reference column, and also for additional columns (after A, C, G, T, N) for indels. Sometimes an indel is even given in mixed case (like "aaaTT").
What is the significance of case in the bam-readcount output?
This is correct. It's looking up the info from your fastq.