Does unconsciously slowing one's prayer and recitation when praying in front of someone constitute showing off (riya')?

If the slowness in prayer is due to one's naturally being flustered when people are present, it is not considered showing off (riya'). However, if the fluster is due to preoccupation with people looking at one's prayer, then this is a form of riya' and hidden polytheism (shirk khafi). The Messenger of Allah, peace and blessings be upon him, said: "Hidden polytheism is when a man stands to pray and adorns his prayer because of a man's gaze upon him." The cure for this hidden polytheism is sincerity and purifying one's intention for Allah the Almighty, and frequently saying: "O Allah, we seek refuge in You from associating anything with You knowingly, and we seek Your forgiveness for what we do not know."