There is another change in the new ISAF Racing Rules. This new rule does not alter the instance of putting a 'lee bow' on another boat. If you complete your tack before the other boat has changed its course, there is no foul. See rule 13 below.
Rule 13: After a boat passes head to wind, she shall keep clear of other boats until she is on a close-hauled course. During that time rules 10, 11 and 12 do not apply. If two boats are subject to this rule at the same time, the one on the other's port side shall keep clear.
Look at the example below, if the starboard red boat calls a protest on the blue boat because of the tack, the protest is thrown out. This is because the blue boat made around its tack beforehand. With this, there is no 'onus' on the blue boat to prove its tack was finished in time.
So now, if you want to protest against a boat that tacked too close, you will need more convincing evidence on the event than you did in the past.