The issue has less to do with you "cutting anywhere near there" -- and more to do with the fact that low voltage wire is simply not made for high voltage transmission. Also, the devices that low voltage wire interconnects are not protected against problems that might occur if they are fed high voltage at their inputs, as they are simply not designed for that (think: audio, video, alarm, control, network) that have the following risk (fire, electrical shock, fried equipment).
Unfortunately, it is impossible to know if you even slightly damaged any of the insulation on the wires you pulled. You mentioned how hard it was and how twisted the bundle became. That observation represents a point of concern.
And then there's the junction box and terminations, where damaged and/or exposed conductors can also happen. In some cases and jurisdictions, low and high voltage can coexist in the same junction box if they are physically partitioned
However, getting back to your principal problem, running AC with DC in parallel is a surefire way to introduce noise into any DC signal, whether it be analog of digital. To avoid noise and interference, AC and DC should never be run parallel and, if necessary, should only cross at 90 degrees.