[anonymousiam]

Any sort of innovation may counter "standards", but without knowing the specific ITU terms for S-band, I can't say whether or not any regulation has been violated.

The fact that somebody saw something pointed at Earth on a frequency generally reserved for uplinks doesn't necessarily mean that it would interfere with other spacecraft receiving the signals from the ground. Starlink (and presumably Starshield) operates in LEO, below most other LEO spacecraft. Maybe they're using a dish or even a phased array antenna, and pointing down instead of up. If so, the probability of interference is low.