According to this morning's Globe and Mail newspaper, "Data from Pearson airport's ground radar and witnesses suggest Flight 358 was nearly halfway down the [runway] before it touched down. Investigators are puzzled at the high-speed [nearly 150 km/hr] overrun, but one emerging scenario is that the [pilot, after touchdown] momentarily reapplied power, perhaps to initiate a 'go-around'". From the way the article (by Paul Koring, who is more knowledgeable in aviation matters than the average reporter) is worded, it seems that none of the above was gleaned from the TSB investigators' briefing: "Officially, the TSB has released very little information".
Rockhound