Originally posted by MindsetMeh. Once Sentry said that he was going to stop holding back, Photon replied with "yeah, that's my cue", then immediately BFR'd him. Imo, his statement heavily implies that he couldn't have handled a max power Sentry, thus he went with the only option he had -- BFR.
I disagree, Photon was never wanting to have a serious fight with Sentry, so he realized he should bfr before there was one. There was no implication of fear imo.