A meeting of Bulgaria's Consultative Council for National Security to consider extending the investigation, originally scheduled for Jan. 17, was suddenly postponed. Instead, on that date Foreign Minister Mladenov was sent on an unannounced visit to Israel. Israel's Channel 2 reported after the meetings with Prime Minister Benjamin Netanyahu and his National Security Advisor Yaakov Amidror that Bulgaria had given Israel a report blaming Hezbollah for the bus bombing.
The office of the Bulgarian foreign minister and Prime Minister Boyko Borissov both issued denials on Jan. 18. Borissov said there would be no comment on the investigation until "indisputable evidence has been discovered," implying that it did not have the needed evidence yet. Nevertheless, over the next three weeks, the Bulgarian government had to negotiate the wording of what it would say about the conclusion of its investigation.
The decision to call the conclusion an "assumption" or even the weaker "hypothesis" about Hezbollah was obviously a compromise between the preference of the investigators themselves and the demands of the United States and Israel. And the discovery of the SIM card could not have caused the investigators to veer toward Hezbollah but would have called that hypothesis into question.
Tsvetanov admitted that the Hezbollah "assumption" had been adopted only "after the middle of January." That admission indicates that the decision was reached under pressure from Washington, not because of any new evidence.