What could happen (and yes I know it never happened to anyone only someone else) is that as there was no sequence line the math would divide by zero and when that threw an error would recover by. randomly pick a line (often the first of the PostMacro) and stay there indefinately.
even with the update vt spam is still there this is a game bug in wow castsequence not gse. I have updated my shadow priest macros with a looplimit of 2 so they work as intended with new gse version.