1) You're reading it wrong. He's using a graphing tool, there's only one value per quarter. He had to put the comment either on the middle of Q4 or on the middle of Q1. From Tomi's point of view, he is trying to show the effect between two quarters, and putting it on Q1 wouldn't really show that because the graph would then read as "it started falling before the Elop effect". Now it's showing the correct effect, but the comment is connected to the peak value, not the actual date - which probably wouldn't be possible in a plotting tool, since there's no value there.

For the placement of the graph to be completely correct he would actually have to have the numbers per 08-11/02/2011, but those numbers aren't available. If he wanted to distort the meaning like you suggest, he wouldn't have connected the comment to the Q4 value, he would have plotted a dotted line from Q4 to 11/02/2011 to show the estimated peak at 09/02/2011, even higher than the Q4 numbers.

2) Q4 2010 was the highest value, where Nokia sold the most smart phones, ever, and still had quite the fine growth in units sold. Q1 2011 saw a major drop. This is no coincidence. Yes, every tech blog and most newspapers on the planet wrote articles about it for a week for every consumer to read, but that's not what ruined the Q1 sales. Not only did the analysts drop everything Nokia like a hot potato, but so did the retail chains and phone carriers. The latter two did have an immediate effect on the sales: they diverted sales away from Nokia over to other products. If they're not selling Nokia phones, then people aren't buying.